Bookmark retention time after source data deletion

Hello,

I have a question regarding the retention time of personal bookmarks in the Power BI Service.
Some of my colleagues have experienced that their personal bookmarks have been deleted from the service. What we figured is that some of the underlying data, which was used in the bookmarks, had been deleted.

So here is my question:
Will a personal bookmark be deleted after some of the underlying information has been removed? If so, how long will the bookmark remain until it is deleted?

The official documentation states, that a bookmark will remain but it should result in a malfunction of the bookmark but not a deletion if underlying data has been removed.
I have tested this in various approaches confirming the documentation.

Here is some information about the setting:

The Power BI report page contains various filters and a main visual which are receiving data from connected dim & fact tables that are stored in an Azure SQL DB. The data is retrieved via direct query.

What I tried to reproduce the disappearance is the following:
1. Delete only the entry in the source table relevant for the bookmark
2. Delete the table (DROP TABLE)
3. Truncate the table
4. Re-upload a new version of the report.

All of the examples result in the outcome stated by the documentation, i.e. a malfunction of the bookmark but not a disappearance.