If Safari works properly when in Safe Mode, the problem can be attributed to a third party software most of the time.
Download EtreCheck: https://etrecheck.com/maspro and post the report here.
Click, “Free Download” button and then “Click to download” button,
open Downloads folder, click on it to open, and then select ”Open”.
Click on the bouncing EtreCheck icon in the Dock.
“Choose a problem” from the popup menu box, and then “Start EtreCheck” in the dialog.
Click “Share Report” button in the toolbar, select “Copy to Clipboard” .
Please post the report here when you reply.
Download Safari Technology Preview and try test.
Safari Technology Preview is a self standing developer version of Safari with some advanced features.
Bookmarks will be automatically imported.
After testing, you can remove it from Applications folder if you wish.
https://developer.apple.com/safari/technology-preview/