Header no longer circle

I tried to upload a new image into the header circle photo but it just turned into a giant square photograph.

I realized it’s supposed to be my Gravatar so I updated my gravatar photo and tried to update the header again. It showed the updated circle photo on the preview and says it has saved+published but when I actually look at my page, it’s still the giant square photo.

I refreshed, logged out and back in again, cleared my cache etc then tried again to customize the header to show my gravatar circular photo + saved but it doesn’t update even though it says “Your design is published!”

Could you please advise? Thanks!