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.
You need to figure out facilitation norms as an organization. Some kind of rule about relevancy, time limits, and an empowered facilitator. Frame interventions as a need to remain focused and to empower all voices. Don't initially present it as a criticism, but as the behavior continues be more critical. Alienate bloviating white boys before the alienate everyone else. OR they might learn a shred of self awareness—I've seen it happen before.