Unable to save Page properties report after mentioning more than 1 user

Summary

Unable to save Page properties report if we mention more than one user in mentioning user filter (refers to replication A).
When the macro is saved, the mentioning user search field saves the username of the user. If you search and select a user by their Full Name, the field will be changed if another user's username is same as the Full Name you entered earlier, the field will be changed (refers to replication B)

Step to replicate A

1. Create a test page then add a page property macro and label the page 
2. Save the page created in step 1.
3. Create another page then add page properties report macro 
4. Click add filter and add Mentioning user filter
5. After adding the mentioning user filter, please add 2 user in that field.
6. Save the macro then save the page
7. After that click edit page and click edit on the page properties report macro.

Observed behaviour

Expected behaviour

The mentioning user filter show the mention user and able to save the macro.

Step to replicate B

1. Create first user with information below:
   • Full Name: Foobar User
   • username: tester1
2. Create second user with information below:
   • Full Name: Second Person
   • username: foob
3. Note that the second user's Username and the first user's Full Name shares the same starting 4 characters
4. Create a Page
5. Insert a Page Properties Report macro
6. Click add filter and add Mentioning user filter
7. In the Mentioning user field, enter Second User and click to select it
8. Second User is showing in the Mentioning user field
9. Save the macro but no need to save the page
10. Edit the macro and check the user in Mentioning user field

Observed behaviour

Mentioning user field now displays the name of Foobar User

Expected behaviour

Mentioning user field should display the name of Second User
 

Notes

• Not just mention user, the Creator filter is facing the same issue as well.
• This probably due to the filter query is combining both user's username in the search, that's why replicate A's result show as blank as there is no match for the search.
• Replicate B's example seems to show the filter field will be saved as Username, instead of Full Name. Therefore another user with Username matching the front few character of the Full Name is displayed instead.

Workaround

Only mention one user under the mentioning user filter.