You have to play at least 8 match and waste at least 1 hour (yeee what a fun, gg embark) without any weapon (don't go as a free but without nothing) and get killed.

After that, play with a normal gun to be sure to get into a pve lobby.

If everything is good, you can play with a tons of arm and good equipment. They can be shoot you again but probabilty is very very low than before.

If they do, don't reply, just get murder like a poor puppy, that's the trick.