No, I have no idea why that would happen.
There is code in the plugins to disable itself incase the Joomla version is 4, and the Joomla 3 version is still installed.
But you have Joomla 3. Do that shouldn't happen.

Can you give me (super) admin and (s)ftp access so I can take a look?
And tell me how I can reproduce the issue.
You can use the 'Confidential information' button in the forum editor to hide sensitive information.

Well, I ruled out that code as the source. So it is not the plugins disabling themselves.
It is coming from somewhere else. So something else is disabling those extensions.
I have no idea what.
It sounds like some malicious code... maybe something is hacked? ?

Or some 3rd party extension doing something weird. But it boggles me that it seems to be very specific in what it is doing.
Again, no idea...

Whatever is doing this, is not even using the Joomla database methods to run the query.
I am at a loss here.
I recommend you look through the database logs to see if you can find anything there (or ask your Host about it).