Same thing happened to me last year. I got very hyped up on the switch. But then it turned into hot garbage.

Tried to get support on the firefox subreddit and they told me I shouldn't be using Firefox Beta if I'm not "technically inclined". Okay, so I switched to the normal release and it was too slow for me to even bother. Back to Google...

I'm wondering if their new quantum engine fixes issues. Are you on that newest version?