X notifier does not log in to my second gmail account

I have 2 gmail accounts. Until now, X-notifier could log in and check both accounts at the same time. Now this is impossible. I have to log out from one account, and log in manually to the other.  And sometimes the x-notifier does not show that i have new unread  income mails. it shows zero new mails.... What can I do  to fix these ?

Check to see if  your Windows OS  or Computer OS  .. Windows 7 is losing support and

people being forced to update to Windows 10 . Delete history , delete cache , do a browser

restore make sure your browser is up to date . Also Gmail wants people to add extra security

to make sure that isn't the issue . For example add a new email and or phone number for 

security for your Gmail accounts cause this happened to me. 

Thank you.

It was the password. The password manager of firefox didn't save my new password for an unknown reason, but now it saved it and i can log in normally. But another problem occured....

It is logging in, cheking both the gmail accounts but it shows new mails only in one of them. The other one shows zero mails. From time to time it shows 20 new emails (!!!) and when i enter the inbox it has no new mail.....

Any ideas for that ?