Scroll not working in gallery image editing module - Minetta

I am developing a website using the Minetta theme (latest version).

When I am editing gallery content blocks, the scroll bar in the pop up window for the gallery doesn't work.

This means I cannot scroll down to reorder images in the gallery.

See screenshot attached.

I have tried on Firefox, Safari and Chrome on two different computers and no luck.

Could someone from Squarespace Dev team please look into this?

Thank you.

Having this problem too and now mine has complete disappeared. 

I'm having the same issue.

Same issue - but note that I am able to use the scroll wheel.