@Nollster01 I'm sorry to hear that none of the above has worked for you.
I've done some reading and came across something that might work: Apparently, for some unexplained and exceptionally weird reason, there seems to be an issue for some players whereby these codes don't work on certain lots. So, as a last-ditch effort, you could try going to different lots and activate the cheat codes there. Once activated they should work until you leave the game (or deactivate them manually), so after doing that, you can go back to the lot you actually want to use those codes on. I know this sounds bizarre, but it's worth a shot.
Let me know if this works!
EDIT: @Bluebellflora Sorry, you posted yours while I was writing mine, so please disregard the first statement of this post.