Strange multi-wan failover issue

[vico1959]

This problem has only started occurring since the last couple of updates. The setup has worked great for many many months up until recently. We are on 22.7.7 currently but this has been a problem for at least this and the last update. Primary WAN is cable and that is pretty rock steady for the most part. Secondary WAN is T-Mobile Home Internet. What happens is I plug it all in and test the failover which works flawlessly and Internet access is great on either WAN and all DNS lookups do fine. I leave it setup and invariably the next morning I have the early birds calling me to say the Internet is down or having trouble so I walk one of them through unplugging the secondary WAN Ethernet and all returns to normal. Unfortunately, I have not been on the premises when this happens so I don't know what OPNsense is saying at the time but when I check the logs I don't see anything that sticks out but maybe I don't have logging setup correctly. Please help me figure this out if you can. Thanks.