Upfront not displaying images

I'm currently using the Fixer Upfront theme and I recently noticed that my background image in two of my sections isn't being displayed. I just tried re-uploading the background image, but it isn't working. I checked the source on my homepage and it lists the following:
data-src-desktop='//www.<site>.com/wp-content/uploads/2016/09/sow_background_960-(1).jpg'

I'm not sure if this is a problem or not.

Also, the image uploader doesn't seem to pop up, but populates at the very bottom of the Upfront page as an unstyled form. Just seems weird to me.

I've given support access if necessary.

Thank you!