WP plugins do not work on CP even though the tag is 100% compatible

I’m sorry I didn’t respond earlier.
But I’ve encountered a new problem that’s even more important to me and I’m struggling with it but I can’t solve it.
I’ve encountered the problem described in THIS thread.
So I can’t log in to my site.
When I log in, it says there’s an error with the password
I’ve gone into the database and changed the passwords manually (so far it’s always worked)
Can you solve this problem?
Or should I try to go back to an older version
Or do I just have to do what I fear the most: leave CP and go back to WP