Try re-verifying steam files for the game, that fixed it for most people. Also use quickjoin, sometimes it can't find a map and size you are looking for due to the limited number of players.
Definitely needs some work, some of the issues are starting to show now that people are playing a lot. Tanks and snipers can lock down the entire map currently. They can also spawn camp so the tanks will just roll in and wait on you to spawn in, once that happens they might as well end the match.
That being said, when players aren't exploiting these issues the game is really fun. Hopefully they can keep it on the right track.