Reordering pages through REST API doesn't work properly

Summary

Updating content especially changing the parent page of the respective page doesn't work with REST API unless the title of the page is modified. 

Environment

• Confluence Cloud 
• REST API

Steps to Reproduce

1. Using the endpoint: https://srandhawa.atlassian.net/wiki/rest/api/content/668827653 and GET method, it will fetch the details of the page.
2. Adding below body text:

   {"title":"Child Page #1",
   "type":"page",
   "space":{"key":"NS"},
   "version":{"number":"2"},
   "ancestors":[{"id":"668991510"}]
   }

3. Refresh the page from UI to observe if there is page reorder operation is performed. You will observe new page version added and the output will return 200 with no updation.

Expected Results

It should move the page under the new parent page.

Actual Results

Nothing changes

Notes

Workaround

1. Changing the title and incrementing the version works like a charm:

   {"title":"Child Page #1 with postman",
   "type":"page",
   "space":{"key":"NS"},
   "version":{"number": "3"},
   "ancestors":[{"id":"668991510"}]
   }

1. The refresh reorders the page here:

   {
       "id": "668827653",
       "type": "page",
       "status": "current",
       "title": "Child Page #1 with postman",
       "space": {
           "id": 647921666,
           "key": "NS",
           "name": "New space",
           "type": "global",
           "status": "current",
           "_expandable": {
               "settings": "/rest/api/space/NS/settings",
               "metadata": "",
               "operations": "",
               "lookAndFeel": "/rest/api/settings/lookandfeel?spaceKey=NS",
               "permissions": "",
               "icon": "",
               "description": "",
               "theme": "/rest/api/space/NS/theme",
               "history": "",
               "homepage": "/rest/api/content/647922129"
           },
           "_links": {
               "webui": "/spaces/NS",
               "self": "https://srandhawa.atlassian.net/wiki/rest/api/space/NS"
           }
       },
       "history": {
           "latest": true,
           "createdBy": {
               "type": "known",
               "accountId": "5b7caf50332df52a5d9449d8",
               "accountType": "atlassian",
               "email": "srandhawa@atlassian.com",
               "publicName": "Supreet",
               "profilePicture": {
                   "path": "/wiki/aa-avatar/5b7caf50332df52a5d9449d8",
                   "width": 48,
                   "height": 48,
                   "isDefault": false
               },
               "displayName": "Supreet Randhawa",
               "_expandable": {
                   "operations": "",
                   "details": "",
                   "personalSpace": ""
               },
               "_links": {
                   "self": "https://srandhawa.atlassian.net/wiki/rest/api/user?accountId=5b7caf50332df52a5d9449d8"
               }
           },
           "createdDate": "2019-07-04T04:43:52.437Z",
           "_expandable": {
               "lastUpdated": "",
               "previousVersion": "",
               "contributors": "",
               "nextVersion": ""
           },
           "_links": {
               "self": "https://srandhawa.atlassian.net/wiki/rest/api/content/668827653/history"
           }
       },
       "version": {
           "by": {
               "type": "known",
               "accountId": "5b970b196d713e3014941aed",
               "accountType": "atlassian",
               "email": "skahol@atlassian.com",
               "publicName": "Swati Kahol",
               "profilePicture": {
                   "path": "/wiki/aa-avatar/5b970b196d713e3014941aed",
                   "width": 48,
                   "height": 48,
                   "isDefault": false
               },
               "displayName": "Swati Kahol",
               "_expandable": {
                   "operations": "",
                   "details": "",
                   "personalSpace": ""
               },
               "_links": {
                   "self": "https://srandhawa.atlassian.net/wiki/rest/api/user?accountId=5b970b196d713e3014941aed"
               }
           },
           "when": "2019-07-04T06:11:55.364Z",
           "friendlyWhen": "just a moment ago",
           "number": 3,
           "minorEdit": false,
           "syncRev": "0.confluence$content$668827653.8",
           "syncRevSource": "synchrony",
           "confRev": "confluence$content$668827653.12",
           "_expandable": {
               "collaborators": "",
               "content": "/rest/api/content/668827653"
           },
           "_links": {
               "self": "https://srandhawa.atlassian.net/wiki/rest/api/content/668827653/version/3"
           }
       },
       "ancestors": [
           {
               "id": "647922129",
               "type": "page",
               "status": "current",
               "title": "New space",
               "macroRenderedOutput": {},
               "extensions": {
                   "position": 238927332
               },
               "_expandable": {
                   "childTypes": "",
                   "container": "/rest/api/space/NS",
                   "metadata": "",
                   "operations": "",
                   "children": "/rest/api/content/647922129/child",
                   "restrictions": "/rest/api/content/647922129/restriction/byOperation",
                   "history": "/rest/api/content/647922129/history",
                   "ancestors": "",
                   "body": "",
                   "version": "",
                   "descendants": "/rest/api/content/647922129/descendant",
                   "space": "/rest/api/space/NS"
               },
               "_links": {
                   "self": "https://srandhawa.atlassian.net/wiki/rest/api/content/647922129",
                   "tinyui": "/x/0YGeJg",
                   "editui": "/pages/resumedraft.action?draftId=647922129",
                   "webui": "/spaces/NS/overview"
               }
           },
           {
               "id": "668991510",
               "type": "page",
               "status": "current",
               "title": "New parent page #2",
               "macroRenderedOutput": {},
               "extensions": {
                   "position": 282425549
               },
               "_expandable": {
                   "childTypes": "",
                   "container": "/rest/api/space/NS",
                   "metadata": "",
                   "operations": "",
                   "children": "/rest/api/content/668991510/child",
                   "restrictions": "/rest/api/content/668991510/restriction/byOperation",
                   "history": "/rest/api/content/668991510/history",
                   "ancestors": "",
                   "body": "",
                   "version": "",
                   "descendants": "/rest/api/content/668991510/descendant",
                   "space": "/rest/api/space/NS"
               },
               "_links": {
                   "self": "https://srandhawa.atlassian.net/wiki/rest/api/content/668991510",
                   "tinyui": "/x/FgDgJw",
                   "editui": "/pages/resumedraft.action?draftId=668991510",
                   "webui": "/spaces/NS/pages/668991510/New+parent+page+%232"
               }
           }
       ],
       "container": {
           "id": 647921666,
           "key": "NS",
           "name": "New space",
           "type": "global",
           "status": "current",
           "history": {
               "createdBy": {
                   "type": "known",
                   "accountId": "5b7caf50332df52a5d9449d8",
                   "accountType": "atlassian",
                   "email": "srandhawa@atlassian.com",
                   "publicName": "Supreet",
                   "profilePicture": {
                       "path": "/wiki/aa-avatar/5b7caf50332df52a5d9449d8",
                       "width": 48,
                       "height": 48,
                       "isDefault": false
                   },
                   "displayName": "Supreet Randhawa",
                   "_expandable": {
                       "operations": "",
                       "details": "",
                       "personalSpace": ""
                   },
                   "_links": {
                       "self": "https://srandhawa.atlassian.net/wiki/rest/api/user?accountId=5b7caf50332df52a5d9449d8"
                   }
               },
               "createdDate": "2019-06-05T11:12:41.726Z"
           },
           "_expandable": {
               "settings": "/rest/api/space/NS/settings",
               "metadata": "",
               "operations": "",
               "lookAndFeel": "/rest/api/settings/lookandfeel?spaceKey=NS",
               "permissions": "",
               "icon": "",
               "description": "",
               "theme": "/rest/api/space/NS/theme",
               "homepage": "/rest/api/content/647922129"
           },
           "_links": {
               "webui": "/spaces/NS",
               "self": "https://srandhawa.atlassian.net/wiki/rest/api/space/NS"
           }
       },
       "macroRenderedOutput": {},
       "body": {
           "storage": {
               "value": "<p>Trying with manual creation</p>",
               "representation": "storage",
               "embeddedContent": [],
               "_expandable": {
                   "content": "/rest/api/content/668827653"
               }
           },
           "_expandable": {
               "editor": "",
               "atlas_doc_format": "",
               "view": "",
               "export_view": "",
               "styled_view": "",
               "editor2": "",
               "anonymous_export_view": ""
           }
       },
       "extensions": {
           "position": "none"
       },
       "_expandable": {
           "childTypes": "",
           "metadata": "",
           "operations": "",
           "children": "/rest/api/content/668827653/child",
           "restrictions": "/rest/api/content/668827653/restriction/byOperation",
           "descendants": "/rest/api/content/668827653/descendant"
       },
       "_links": {
           "editui": "/pages/resumedraft.action?draftId=668827653",
           "webui": "/spaces/NS/pages/668827653/Child+Page+%231+with+postman",
           "context": "/wiki",
           "self": "https://srandhawa.atlassian.net/wiki/rest/api/content/668827653",
           "tinyui": "/x/BYDdJw",
           "collection": "/rest/api/content",
           "base": "https://srandhawa.atlassian.net/wiki"
       }
   }