MS 365 Outlook can not access Comcast IMAP server when connected via Carolina Connect network

I'm using MS 365 Outlook for my email on a Win11 laptop.

This works flawlessly everywhere I go, except for one location which has Carolina Connect as the ISP. 

When I am at this location, Outlook can send and receive my Comcast email only some of the time.

Most of the time, it can not connect to imap.comcast.net and I get error message 0x800CCC0E.
When it is not working, I can disconnect from Carolina Connect internet and switch to hotspot and it will work that way, but with slower response speeds.
When it is not working, I can still access my Comcast email from a web browser (Firefox and Chrome) but not from Outlook.

I do see that Comcast changes the IP address of imap.comcast.net frequently and wonder if this could be part of the problem.
Sometimes, when it is not working, I found that if I change imap.comcast.net to the current IP address, i.e. 96.118.57.80, then it will ask me to accept an unverified certificate.  If I accept this certificate, then I can use Outlook for a while but it will eventually stop working again.

Any idea what the problem could be?   I think that I have tried every solution found in this forum and on the internet.
I don't know why it works some of the time.