I have a similar issue with my RBR850 but I'm on V7.2.6.21

FURRYe38​ ,

Waited until this AM to do the 30-30-30.  Prior to that I noticed that there wasn't the magenta light I'm use to seeing lately but none of my devices could find the internet (wired still worked)

did the 30-30-30 with the satellite in the same room (I only have the one satellite).  Never could get it to go solid white and tried some variations to see if I could get it to work:

First try, flashing white then blue.

Tried the "Add Orbi Satellite" From the RBS web page and it failed

Second, did the 30-30-30 again, never presented a solid white light, flashing white then blue.  

Tried the "Add Orbi Satellite" From the RBS web page and it failed

Tried a factory reset (not 30-30-30).  Flashing white then blue, never solid.  Failed the Add Orbi Satellite but shows connected in attached devices.

Waited for about 10 min before  moving it downstairs.  Observed: Orbi app and web interface shows connected at 5GHz, 8 devices attached to the satellite.

Attached wired devices (not backhaul), within a minute solid blue light, lost wireless (blue light, not magenta) but wired devices work.  Removed wired device and RBS wireless back up.

seems like a smoking gun to me:)

Starting to remove/troubleshoot 'wired' devices attached to RBS: Hue Hub then Netgear SW with: AppleTV, Apple AX, Samsung TV, Denon AVR, McIntosh Multiroom amp (normally off).  Nothing has changed in a few years but the Samsung TV, which was replaced a month or so ago.

I'll report back