Firefox 79 and Gmail
This started when Firefox updated to 79. Now, after I open Gmail, a minute or so later, usually after reading or replying to an email, Gmail disconnects from the internet connection. I get a message at the top of the screen,
When I exit Gmail. it asks if I am sure I want to leave the page. This indicates to me that there is an action pending in Firefox or Gmail. When I restart Gmail, the messages that I deleted are still available, marked as read. These may be the pending actions that generated the "Are you sure" message. Once Gmail exits, nothing else works in Firefox, The only way I can continue is to close and restart Firefox. I do not have the problem in other browsers.