satellite deco stuck on loop of solid yellow - blinking yellow - solid red - blinking red then back to yellow again.

This has happened to my deco m4r and deco x60

I've tried to factory reset the satellite deco, however when trying to set it up, the main deco cant find this satellite deco even if it is right beside each other. Help please.

Solution to the deco m4r was a replacement unit

device list

Isp modem/router

Deco x60 (3)

Deco m4r (3)