Image manual polygons are not working

For some reason, I cannot draw polgyn shaped boxes in image manual. I cannot close the loop so to say - Prodigy doesn't register when I try to finish the polygon, but it keeps on drawing a new point. Is this a known issue?

How to reproduce:
Clone the git repo
python -m prodigy image.manual test png/ -F image/ in a shell where png is a directory containing png pictures.

Hi! Can you double-click (or click again on the current point) to close the path? This is an extra feature I implemented, to kinda mimick the behaviour in Photoshop/Illustrator.

The manual image interface is still considered a bit experimental, especially when it comes to the precision annotation features. What operating system and browser are you using?