By baiting, I mean posting deliberate dog whistles, often as crude proxies of what they fear and hate, and set off what is sometimes hours of chud barking in that area, whether it's a game's lobby chat or Discord or whatever.
Examples I've seen include old and exhausting shit like "did you just assume my gender" and "check your privilege, shitlord" 4chan greentext-tier staleness, but sometimes they can get slightly more cunning and insidious, such as portraying themselves as farcical LGBTQIA+ people then announcing an intent to do (conspiracies/crimes that chuds accuse LGBTQIA+ people of here) and keep up the whistling until every chud is barking across the site.
I do play some online games and calling out bait sometimes works, but it's still exhausting when a cooperative game shuts down because some chud starts a hate rally and effectively shuts down the game's cohesion for a while. 
Straight up just tell them they're an uncomfortable person and offputting and disengage go the extent possible. Most people acting like that on the internet are seeking approval or validation from others and think those views and opinions are the way to get them. If they don't get the response they want, they'll change how they behave until they do.