I've had a few events so far where the discussion/feedback part had 1-2 white guys doing longgggg monologues about something unrelated to the main topic. Last time had some stoner guy ranting about the confusing service at airports here (the event was about Gaza). Before that it was some boomer guy trying to explain Madonna to the non-white teens in our group (the event was about trans rights). Sometimes it's just two white guys monologuing back and forth. It's super counter productive and cringe.
I'm just thinking of a hard rule. Like "if you're a white guy, you're welcome, but please try to listen more and keep unrelated monologues to a minimum."
For the record, I am a white dude.
Don't you have any officers, old guards or just well respected members to explain this to them? They kind of just seem like yappers and if they don't stop after being asked politely then they need to be reprimanded and turned away if they fail to stop. If they're good faith comrades then a good faith discussion will stop it. If they aren't then you rooted out the problem that was sort of sabotaging your meetings anyway and they needed to go.