Orbi RBR 853 satelite changing colors all the time. What does it mean. Also ? wired backhaul

I have an Orbi RBR 853 ( Router and two satellites) The first satellite is place about 60 ft in another room in the center of the house and also has a Cat 8 Ethernet cable used as an Ethernet back-haul.  The second satellite is placed about 40 feet beyond at the opposite end of the house in a wireless configuration. The intended use is a "daisy chain" network.  The second, farthest placed satellite appears to work but is constantly changing led colors on the front.  It will pulse white for about 8 times then change to solid blue. Then go back to pulsing white for about 8 times then go to solid blue.  It does this repeatedly all day.  The Orbi App will show either wireless connection to the satellite or the main router.  When I first setup my system a year ago, it did not behave this way.  Only recently am I getting the pulsing white, solid blue led show.  Any idea what to do?  I know pulsing white is the system updating configuration and the solid blue means a good connection.  Is the satellite alternating connection from the other satellite to the router? Just trying to figure out what is going on and how to stop it if I need too.

(another question): do I need the Ethernet cable back haul or will the Orbi wireless back-haul be enough?