Unable to move a page with child pages to a new parent page on same space

Description
The customer is unable to move one particular page called "UCDP" and 11 child pages under it to a new parent page within the same space. When you click Move and set the new parent page, it does nothing. Also was tried through Browse-Page-Reorder all pages and yet no luck. Other pages work fine.

During our tests, we’ve moved manually the child pages though Browse Reorder. Almost all of them were moved except one that has 2 child pages under it with several child pages under each of the child pages.
This bug may be related to this fixed bug. However, it was fixed on version 5.4.x and we are getting the same behaviour on version 5.6.6

Workaround
The steps below are the same from this bug that was affecting version 5.4.x.

1. Stop Confluence
2. Backup Confluence database and Home Directory.
3. Run the following SQL query to copy the PAGEID values into the CONTENTID column

   UPDATE NOTIFICATIONS SET CONTENTID = PAGEID WHERE PAGEID IS NOT NULL;
   

4. Run the following query to drop the PAGEID Foreign Key constraint (double check the actual key name in the NOTIFICATIONS table)

   ALTER TABLE NOTIFICATIONS DROP FK594ACC88C38FBEA;
   

5. Run query to drop the index on the PAGEID column

   drop index NOTIFICATIONS.n_pageid_idx;
   

6. Run this query to drop the actual PAGEID column

   ALTER TABLE NOTIFICATIONS DROP COLUMN PAGEID;
   

7. Start Confluence
8. You should now be able to purge the trash, able to successfully delete any space and the page watchers are listed in Watch > Manage Watchers