Getting random "Unable to connect"

[tashaThunderbird]

Firefox 70 (64-bit), windows 7

These connection problems started a couple of days ago. Firefox will work OK for many hours, then report "Unable to connect". But I can connect using Chrome. Then after a few minutes, connections start working again. I have FF configured with "no proxy". I have no windows proxies.

New problem as I'm typing this (using Chrome):
I just clicked on something in FF and it is giving me a new error:

The proxy server is refusing connections

Firefox is configured to use a proxy server that is refusing connections.

Check the proxy settings to make sure that they are correct.
Contact your network administrator to make sure the proxy server is working.


What proxy server is it talking about? I have FF configured with "no proxy".

How do I find out what proxy server FF thinks I have?

Thanks!

PS: I waited about 3 minutes, clicked on a link that failed 3 minutes ago, and now it works. Very confusing. Any and all ideas are welcome.

[malliz]

What Anti Virus and or security software are you using?

[LIMPET235]

Off to Firefox Support with you...

[tashaThunderbird]

What Anti Virus and or security software are you using?

Norton anivirus