I haven't tried the base game without forged alliance but in forged alliance atleast, I can't make control groups of units at all, I can still make groups of buildings but not for and fighting or repair units. wth? I can't even get through a tutorial like that, I tried the tutorial and tried it in a skirmish game, I can't make control groups.

Wait... so you can't make control groups of units... but can of buildings???
Well that's certainly strange. Unfortunately I currently don't have SupComFA installed on this computer so I can't look into settings and whatnot. Do have it installed offline though. Will check, hopefully, tomorrow.

Side note: dunno if that changes anything but you might want to look into Forged Alliance Forever:
https://www.faforever.com/play

Just tested. No result. Ctrl + 1-9 all make groups and they appear on the right screen side. There is also no setting in options where you can change control groups -- by all right - your problem shouldn't exist! Since keybindings also cannot be changed - I would advise a reinstall. Sorry, but you seem to have a very strange and random bug come up. :<

Check your keyboard language. Some games can be finnicky with languages where the default action for the 1-0 keys is something else and not a number. No idea what german keyboard layout looks like, but in czech for example, the 1-0 keys are + ě š č ř ž ý á í é, by default. Most games can dynamically adjust their keybindings to recognize that, but from experience, I've encountered it multiple times, in games both old and new, where they got confused by this and I had to either redo the keybinds or switch to a US keyboard layout.