Since none really reported this on the forum yet I guess I'll do that.

Small scaled bosses have this weird bug: collisions between players are inverted, people on the red team keep bounching and getting stuck in each other while on the other hand the mercs can't make contact with the boss model, they pass thru him like they are teammates.

In some maps this can be very annoying since it can be hard just to get out of spawn, goombas don't really work and it's difficult to walk around in general without getting sucked into someone else . Sometime people just kill themselves just to not deal with these bosses.

Fairly sure this problem happens only with Stewie, Munch and I think there is a 3rd boss which I can't really recall right now.
This might not be nice but I suggest removing these bosses for the time being.

Support.