When I lose and try to restart the map for some reason, it keeps saying "mission failed, press fire to restart." I can move and shoot, but the rest of the characters are still and can't be damaged.

also when I have to restart by choosing the singleplayer option it doesn't save that I beat Enker's level and I have to see the cutscene every single time.

I was able to replicate this, can you try loading this as an additional file to see if it fixes your problem?

Download Patch