Wordpress charsets from hell

I know I should be coding instead of helping friends get their useless blogs together.
But I helped this friend for a while with getting their site online, backing up, stuff like that.
The blog is huge, it has been around many years, so quite a big database.
They usually write some posts against a group of bad people so SQL injection happened a few times and also DDOS.
But they moved the blog on some more secure server.
Anyway, recently they noticed some of the posts had weird ? characters. Others were not affected.
Googled the heck out of it, ran SQL queries from the PHP admin panel ( I don’t have SSH access ) , installed some plugins to do the job but nothing changes.
I had helped them with this a few years back, but changing the charset for the posts table to UTF-8 did the trick.
Not this time.
I really, really, really, really, really hate Wordpress.
If I could just change it to some other nicer CMS I would. But I’d have to import all the database…
L.E. If the solution is this:
https://codex.wordpress.org/Converting_Database_Character_Sets
I won’t.

I’ve a love hate relationship with wordpress, I love that i can have a bare bones blog up and running in 30 minutes or less. I don’t love that it takes me hours to fix the stupidest little php issue or even just diagnose what could be the issue. Thanks for the link, i’m saving that for the future lol.