I changed my PNG file to a GIF file in the banner section of the setup and it took over 5 minutes to update on the EWP.

Immediately after updating the file, I saved the changes and refreshed the page. Then I looked at the EWP but the banner was not updated.

I saved it again, signed out and back in, and tried to preview it on the EWP. Still, it did not update.

I signed out and waited about 5 minutes. Then, I logged in, looked at the EWP, and it updated.

I'm reporting this because if this is possible to improve, we might spare customers from getting confused or frustrated.