Cannot play multiplayer since other people cannot join. Double checked mods and we matched.

That is really weird. I could play MP during playtests. Are you running a dedicated server or just hosting over Internet/LAN?

It does sound like a common bug that I've had with some friends before. Did you guys try to switch who the host was (say you were the host and they couldn't join, perhaps switching it up so that one of your friends hosts the match)? Hope this helps :D

As soon as I reached the town where the US Paras are, most of them were dead and there was a german APC sitting in the middle of the street shooting everyone on sight.

The German armoured car is on a trigger when you get close enough. (i.e. it shouldn't rush the paras too fast). Sometimes, however, it gets there and annihilates everything, sometimes it stops further back and sometimes it takes forever to get there. If the AI was more consistent it would be easier to keep it under control but as of now I am far from skilled enough (if it's even possible) to write a script/code to persuade the AI to stay further back/slow down consistently. I could of course remove the car full stop, but IMHO it would be less enjoyable. If you and/or others think it's not an enjoyable enemy I can remove it. Thanks for the feedback regardless, it's much appreciated!

Quick edit: Perhaps if it would lose the autocannon would it be more fun/balanced? Sure, MG's are deadly AF in Arma but not as much as a 20-30mm tube of death. Removing is still an option though.