I did a Firefox upgrade last week and it is bleeding out into my memory terribly!!! I.e. using up massive amounts of memory!
I don’t know if I am doing something wrong, but I am considering uninstalling it completely as it is so frustrating that I have to keep checking the Task Manager to see how much it is gobbling up and close it down several times daily. For me it is almost unusable.
Memory Restart https://addons.mozilla.org/en-US/firefox/addon/memory-restart/ Shows how much ram FF is using, and enables easy restart to flush memory.