Thank you for replying and for taking a look.
I just sent you the recent version and I believe it has to do with travelling down to new areas from ladders and falling to the screen below.
I originally encountered it here (1st red block) and removed the ladder completely to see if it was just that screen, then it began to happen in the cave area below when you attempt to travel down to new areas.
I do not think its an issue before these areas because you are always travelling up to an new area. The final areas of the demo have you travelling down and sometimes you get stuck in a crouch position while on the ladder and that is when you are disconnected and fall through. With that said, It can easily reproduced in other areas, just by backtracking to previously explored areas beneath you.
Thank you again Dale!