Honeywell thermostat no longer connects to Xfinity Wi-Fi

On 6/30/25 my honeywell thermostat dropped its connection to my xFinity router.  It has been functioning fine for nearly 2 years.  I've restarted both the thermostat and router, and attempted reconnecting 4 times.  Message is that the connection attempt has timed out.  I called Honeywell support (Resideo) and they suggest perhaps their IPs need to be white listed by xfinity.  Not sure why this would be so all of a sudden but that is where things stand.  Everything else connects just fine to the router.

Here are the IPs Honeywell suggests whitelisting:

If there is a firewall, make sure the thermostat can connect to the following connection points:
TCC – App/ Portal Devices
tccprod01.resideo.com - 20.7.235.10
tccprod02.resideo.com - 20.62.30.72
tccprod03.resideo.com - 20.62.29.159
lyric.alarmnet.com
chil.cloudapp.net 
*Network Admins can "whitelist" these endpoints within the Security or Network settings of their networking equipment*

Any suggestions?