Ever since Ubuntu **bleep**ed up firefoxby moving it to a snap it's been garbage. Currently I am using And I am constantly being interrupted with "close browser now for updates", random lockups in the middle of watching videos, composing a message. ...
Since Firefox has gone to a snap installation on Ubuntu it has been extremely flaky and unreliable, your tab crashed, can't access this or that library, and basically gets in a state where it's broken until I reboot. It NEVER did this back when...