Images disappearing in prototype

Hi! Some of you guys seem familiar with Figma.

I have a prototype where all images are visible on desktop, but on all phones they’re gone (see pic). Deadline is early tomorrow. I have tried flattening (then I only see the shape of the mask). Then I tried exporting all of them as pngs to get rid of 1000 layers, and also reduce image size in Photoshop; neither of them seem to work. Read about cache in a forum, but haven’t tried as I’m scared to lose stuff now right before exam. 

Ideas?