Spinning beach ball problem

I keep getting the spinning beach ball whenever I use Firefox these days.

I've reinstalled my OS. I've restarted my laptop in recovery mode, used disk utility and then 1st aid...but the problem always reappears. I always check my laptop for malware before logging off.
All my software seems up to date...

Short of ditching Firefox and using Safari...does anyone have any ideas as to how to stop the beach ball?