I have been having the exact same problem. I haven't played in about a year, I only jumped back in when I seen the Heavy Metal update. Before I could easily win 2 or 3 out of 5 games as an antag but now it's more like one out of ten. Yesterday I went from 43 mmr down to 20 mmr without a single win.

The mission difficulty shouldn't change because there is an antag in the match it should be an extra challenge. The way it is now, I hope for an antag to join because the mission is so much quicker. Bosses melt and objectives only take half the time to complete.

The main problem I have is the respawn timer of the antag. 15 seconds + another 5 to load because of ping and then I'm forced to spawn at the opposite side of the map and have a other 10 Sprint to reach the raiders. Almost every encounter now is a 4 V 1 gang bang.

Also missions like a fistful of sand spawn the alaph beside the raiders in the final area. If I do happen to nearly kill the protector they just jump on a box grab the alaph and top his health and shield off.