I had the same issue with Safari 14.1.2 on Big Sur 11.5.2. Emptying Caches via the Develop menu solved the problem for me:
Preferences > Advanced > Show Develop menu in menu bar
Develop > Empty Caches (option+command+E)
James2
Users receive reputation points by contributing quality content to the forums.
Posts include post and replies published on the forums.
Post authors can mark replies as Accepted to indicate successful solutions.
Apple Developer Forums admins can mark replies as Apple Recommended to indicate an approved solution
User for