Ring pro doorbell repeats set up modem

I have had a replacement ring doorbell pro sent to me due to old one the button had cracked so this is a Like for like replacement. The I run through the set and it tells me it’s all connected ok the dashboard view even updates then 5 minutes later it’s off line and has entered the set up mode again saying please follow instructions in the app. I have gone through this process 10 times same result. I have removed the device tried a hard reset connected it directly to Wi-Fi instead of pro chime network same result. I beginning to think I’ve been sent a detective replace my.