For a few rundowns now this has been happening, and verifying and fresh installing the game doesn't fix it. Not sure what else to do. After trying to change the bot's loadouts a few times, if I leave the expedition and try to launch another one, it doesn't load me in and I have to restart the game. Bots work fine if somebody else is hosting.
You can notice in the pic the gun and tool selections are greyed out, I can't change those at all. I can go into the melee select, but it doesn't actually change their melee after I apply one. Sometimes they also don't fill in the slots, even though it clearly says "Players and bots". If I change it around from just bots and players and bots, one will eventually join, but I still can't change their loadout.