For the last few version of Firefox (currently 81.0.1) and latest XN (4.2.20) I keep gettng my Gmail accounts signed out. I clear all cookies and cache, resign in to my 10 Gmail accounts, shut down Firefox, restart and Gmail/XN do not get signed into my accounts. I manually sign in again, and when XN checks my mail again, I get signed out of Gmail accounts. Anyone else experience this?
Cookies
Did you set the option to delete all cookies when closing Firefox? (You should not!)
(about:preferences#privacy -> Cookies and Site data)
Cookies and Logins are 2
Cookies and Logins are 2 things I don't delete. The problem began wth the last few versions of Firefox. Everything I tried before doesn't work. Basically not allowing XN to check my GMAIL now and just checking my 10 accounts one at a time from my main account.
Suggestion
Logging out can be part of the X-notifier process, but should only be used in old scripts that do log in successfully. Logging out from one Gmail account causes logout for all. I suggest you find out which one(s) of your 10 accounts get(s) logged out by X-notifier by enabling them one-by-one in X-notifier Options (using the checkmark in front of every account in the list).