Hey, thanks for letting me know.
I've seen this happen recently while my daughter was playing it, and a couple of other people had pointed this out as well. It usually clears itself after save+quit and reloading - so I'm not sure the save files would help at this point. But I'm going to take another look at the new(ish) code related to the base module construction and try and get that fixed soon as I can.
95% sure the game thinks there is an entity / object / player standing in the way, even if there visually isn't anything there.