Safari 15.3 installed with Big Sur 11.6 as OS and does not work as it should

I have gone through the Apple help guide "If Safari on MAC doesn't open a web.....isn't working as expected" and I still can't get Safari 15.3 to work.

I suspect it may be related to incompatability with BigSur OS 11.6.3.

About 2 weeks ago I attempted to upgrade to Monterey, but I don't have enough storage space. So I uninstalled Malwarebytes and deleted as many files, etc. I could to make more room.

BEFORE I attempted the Upgrade to Big Sur, I updated Safari to Verrsion 15.3. I might have caused the problem by doing this FIRST, before upgrading to BigSur. Unfortunately, I attempted the OS upgrade and couldn't install it due to lack of space.

I have a MAC Book Air, 13 " 2019. I currently have 32 gigs available out of the 121.