I just got a new M2 MacBook Pro.  It's the first wifi 6 device I've had on my network.  It has major wifi connection stability issues.  It varies from dropping me from Google Meets periodically to being unable to access the Internet at all.  My mesh looks like:
 

• Fiber modem + router
  • Deco x20 #1 [ethernet]
    • Deco x20 #2 [wifi]
• Switch
  • Deco x20 #1 [ethernet]
  • Deco x20 #3 [ethernet]
    • M2 MacBook Pro [wifi]

In other words, I have the main Deco wired to the router, one remote Deco on wifi, and one remote Deco using the ethernet backhaul.

The behavior I see is that when I'm experiencing connectivity issues, it's because the MacBook has switched from the local Deco (#3) to the next closest Deco (#2), which isn't close enough to give reasonable bandwidth.  I've even seen it then switch to the furthest Deco (#1) and report that it has no Internet access.

I have solved the problem by running an ethernet cable from the MacBook to Deco #3 and disabling wifi on the MacBook.  That gives me a stable connection, but it means I have a cable draped across the room.  It's also silly, because I bought this mesh specifically to support wifi 6.

I would love some help figuring out how to get the MacBook stable on wifi 6 with the Deco mesh.