Orbi Wi-Fi not connecting to Xfinity server

[RHATX]

Our email with Xfinity on iPhones won’t work on our Wi-Fi system with Orbi. If we turn off WiFi, and use cellular, all works fine. G Mail works fine with Wi-Fi, so it looks like a connection issue between Orbi and xfinity. Suggestions?

[plemans]

suggestions? 

1. turn off private mac/ip address. Disable icloud relay

2. Try a different DNS Server. Here's a few. Also remember to change the ipv6 dns server if ipv6 is enabled.
CloudFlare
IPv4: 1.1.1.1 and 1.0.0.1
IPv6: 2606:4700:4700:0:0:0:0:1111 and 2606:4700:4700:0:0:0:0:1001
GoogleDNS
IPv4: 8.8.8.8 and 8.8.4.4
IPv6: 2001:4860:4860:0:0:0:0:8888 and 2001:4860:4860:0:0:0:0:8844