You didn't mate. Please check your transaction history before making a post, most of it is simply confusion.

What about my case? Is it some bug or did I make some sort of mistake?

Make sure you're using a Steam client and it's properly updated. You also have to be connected to the internet when you launch the game.

I recently changed to the steam version before the daily tc rewards update, and I set it to high priority but it didnt really seem to work. It's toribash 5.2.

I have gotten the message to claim the 800tc reward twice today, only paid out once.

That's normal, you are supposed to get paid once regardless of how many times it shows up

Asking about mine again, is it some sort of bug or missing file?

No update yet, can you try claiming it on an alt account / different PC?
Not sure what might be causing the issue for you, can't check properly while it's holidays.

It's ok, we all have our personal lifes. I just tried it on a different account and different internet connection, did not work, I have not tried the different PC though, but if I reinstalled the steam version once, and I'm using the standalone right now, I dont think it's a PC problem either.

It isn't exactly a PC problem, rather a way how the system looks for alts.
I'll PM you with more info now.