@Bounce Yes, I have. I even completed a couple of missions traveling alone afterwards as well, but even then, they're hostile.

That's strange. Have you tried waiting 30 days in an area away from both Danse and other BoS members?

@DCShannon 30 in-game days, yes? No, I have not. Does waiting that long make any sort of difference?

@MavisEverdeen That resets any cells not currently loaded. In other words, it recreates all the areas you're not at. If the BoS members are mad at you, but shouldn't be, then once you wait and return they should be reset and okay. This can fix most things in the game.

@DCShannon So,, should I try completing a side quest alongside him, dismiss him, wait for 30 in-game days, then fast travel to say the Prydwen, and then see if they attack?

You shouldn't need to do the side quest. Just dismiss him, make sure you're far away from him or the other Brotherhood members, then wait. An interior area should work, or just far away, like the Crater of Atom. If that doesn't work then I don't know what's up. What platform are you playing on?

I asked him to travel with me, walked around for a few seconds, dismissed him, then travelled to the Prydwen, but nobody shot. Apparently they only attack if I've been around him for extended periods of time. I'm playing on the Xbox one

So they're not attacking you now?

Yes, but only because I'm not traveling with him. If I do, for an extended period of time, and dismiss him, the brotherhood will attack.

This includes the completion of side quests

Huh. Well they're supposed to be hostile when he's actually with you. Maybe if you wait a day after dismissing him? Or maybe you're encountering BoS members when you're with him? You'd probably notice that, I guess

When you dismiss him, there should be an on-screen message stating that you are no longer hostile with the Brotherhood of Steel. Is that showing up for you?

Nope. I almost never get those "[insert message here]" notifications anymore nowadays,, :/ Back when my game was working and I encountered knights of vertibirds while traveling with Danse, nobody shot at me, and I shot at no one

Unless its a "[(this guy) is going to (this place)]" notification, that is

If you're not getting the "You are now hostile to the Brotherhood of Steel" and "You are no longer hostile to the Brotherhood of Steel" messages when you take on and dismiss Danse, that would seem to indicate to me that either you're permanently hostile, which should only happen due to story decisions (I think), or something's bugged and it's not flipping the switch. At this point I can't really help except to suggest tests. If it were me, I would probably just stop taking Danse with me.

I'm heading out, so I won't be signed into SE until tomorrow. Good luck.

Probably just another bug,, thank you very much for your help.