What affects Personal bookmarks?

Hi community,

So I am using PBI service and the customer I am working with are using personal bookmarks for some of my reports.

Recently I got some complaint that a change I made impacted their personal bookmarks, either it got removed or stopped working properly.

So I went online to try to find out what changes I can and can't do in the reports when it comes to affecting the users' personal bookmarks. I quickly found this page: https://learn.microsoft.com/en-us/power-bi/consumer/end-user-bookmarks 

But it doesn't really specify what specific changes in reports that affect personal bookmarks. It just gives some examples and says something like "...If the designer makes major changes to the report...". I would like to know more specifically.

So my question is two parted: 

1. Is there any official microsoft documentation for what changes in reports affect personal bookmarks?

2. If answer is no for above question, does anybody have some sort of list of what changes affect the personal bookmarks?

I would like to know in order to prepare customers for when I have to make changes that actually affect their bookmarks.

Thanks in advance for any help or guidance in the matter.

Sincerely,

Niklas R