Customizing Confit freezes in 'saving changes'

Hello!
I’ve searched high and low but no answers to my issue:

When I go to customize the background photo on the Confit Theme, it allows me to upload a new photo, but when I click ‘save’ it it gets stuck in the ‘saving changes’ sidebar message and the background image never changes (even though it shows up as the new image while on the customization page).

Here is the site in question – https://filipalasabrosa.wordpress.com/
The white/grey cloud photo is the first one I uploaded and was able to set as the background image; since then I’ve tried to change it many times with different images and always just get the unending ‘saving changes’ message.

Is this a known issue?

By the way, I WAS able to change and save other items in customization, like the menu and the post page and setting the static homepage. But the ‘saving changes’ message never goes away.

Thanks for your time!!!