Orbi router shuts down

My 4 year old Orbi AC2200 system that includes an RBR40 router, two RBS40 satellites, and one RBS20 add-on satellite began shutting down in a random fashion two months ago. I am considering replacing the router with an RBK50. I believe the two RBS40 satellites from the orgininal system with work with this new router. Do I simply synch these with the new router like I did when I added the RBS20?

The original system covers an area of about 4000 sq. feet including an upstairs recreation room, and I was able to connect with my Spectrum download speed of 114mbps from anywhere in my home. I briefly tried an Orbi AX4200 system with two satellites but it was unable to provide this download speed or accomodate my needs (the back haul of my most distant satellite always registered as poor). I therefore was able to return the AX4200, and my choices are trying the RBR40 or moving on to an Orbi RBK853.

Your input is appreciated.

WiFiDoc