RBS50 thinks it's wired to another RBS50 Satellite

This seems to be a problem with Orbi and am relieved that someone else is experiencing this issue.  I posted about this before and there wasn't a solution although the last firmware update does claim to contain fixes specific to Sonos but still this issue persists.  As you noted this does impact the performance of Orbi and so is a real problem not just a cosmetic one.

We have one wired Sonos device which is a Sonos Soundbar and all other Sonos speakers connect wirelessly (although Orbi always reports them all as wired devices I presume due ot the Sonos mesh network connecting all other Sonos devices through the Soundbar). This is the solution I have which works for me but is far from ideal.

Turn off the sattelite that thinks it has wired backhaul and unplug the ethernet cable that goes to the Sonos device.  Now power on the Orbi sattelite and wait until it connects and stablises using wireless backhaul.  I usually wait 10-15 minutes and check the Orbi app or admin pages to make sure it shows as wireless.  Now plug in the ethernet cable for the Sonos device again and check Sonos is working.

The Orbi sattelite should now keep showing wireless backhaul until the next time the sattelite is restarted/power cycled.  This works for me 100% of the time but is a real pain due to manually unplugging/plugging in the ethernet cable.  I've seen the wireless backhaul work without going through this process but I'd say it is rare so I always follow this process.