Orbi RBK50 - connection lost throughout day

Equipment - Orbi High performance AC3000 Tri-Band WiFi System (RBK50)

AT&T Modem - Pace Model 5268ACFXN

Internet Provider - AT&T Fiber (Broward County Florida) - Getting 892.89 Download and 942.67 Upload speeds at time of writing this post

Ever since I installed my Orbi (One unit in my home office and the other downstairs in my bedroom) I have periodic loss of internet throughout the day.  I called AT&T and they came out on 3 seperate occassions and each time tested all the connections on their end and they worked perfectly.  They also ran extensive tests from the network and found no errors or outages - they claim my issue is some sort of IP conflict between the AT&T modem and my Orbi.

This issue is very frustrating as you can imagine and the problem seems to fix itself after about 3 to 4 minutes but it happens several times throughout the day and I work out of my home so it needs to be resolved.When the problem occurs I get the message "Gateway Authentication Failure" - and as stated earlier I don't do anything and the issue resolves itself after a few minutes.

Any help is appreciated.