Press Command + Option + E on your keyboard to empty the Safari cache, then quit and relaunch Safari to test.
If that didn't help, go to Safari > Preferences > Extensions. Turn that OFF, quit and relaunch Safari test.
If that didn't help, open a Finder window. From the Finder menu bar click Go > Go to Folder
Type or copy paste the following:
Click Go then move the Cache.db file to the Trash.
Quit and relaunch Safari and test again.