Orbi RBS350 second satellite not connecting to router

[Zeus44]

I just bought a second Orbi RBS350 satellite to use with my existing RBR350 router and satellite. But following the Add Satellite instructions isn’t working. The LED on the new satellite always just goes from flashing white to magenta when I press sync. Even when the router and the new satellite are in the same room.
Any help to get it connected much appreciated

[FURRYe38]

Did you turn OFF the working RBS first then try to sync the incoming RBS?

Possible the incoming RBS FW is not the same as whats on the system.

Can try ethernet connecting the RBS to the back of the RBR and see if the RBS gets an IP address from the RBR. Use this IP address to log into the RBS web page to update it directly with a wired PC. admin and password would be log in. 

That fails, you can try this:

https://community.netgear.com/t5/Orbi-WIFI-6-AX-AND-Wi-Fi-6E-AXE/Orbi-WiFi-6-AX-and-AXE-Frequently-A...