My first encounter worked fine. I redesigned the level portion the encounter takes place in so I deleted the original three lvlbandit*s I had placed and now the new ones won't attack unless I try to initiate a conversation with them. I checked their faction and it was set to none so I set it to BanditFaction and still they won't attack. They all have the masterambushscript.

They're set up with simple two point patrols and they navigate those with no problem.

My follower can go anywhere I go in the level as well.

I've actually encountered this bug with retail bandit camps as well but those are random and unrepeatable whereas this problem in my custom dungeon is persistent.

It's not a bug. How is their ai data set? The best it not to use the template ai data; just give them "personal" ai data.

Exactly as ladyonthemoon says, the template actors have "fixed" forms with only varying levels of aggression/level. Make a few bandits like MyBandit1, MyBandit2, etc, give them varied appearances and clothing and drop them in game, rinse and repeat. I did this, as many do, with guards in my city. At any one time there are up to 12 guards around but only 4 variations of them exist, Guard1HwShield, Guard1HnoShield, Guard2H and GuardRanged.