Hi, welcome to the forum!
I can't open your links "Secure connection failed" error), but if I had to guess it sounds like this might be caused by the player sprite rotating and having it's origin at the bottom instead of center (resulting in the rotated sprite somehow getting stuck inside the solid floor, before it can rise up by gravity). You can either try using the "Push out solid" behavior on player, set the origin point of player sprite at center (or rotate around the center of sprite/set position on rotation), or on gravity flip set the player character Vector Y to a negative value (-500 or something depending on what you need) to help prevent sprite getting stuck.
But again, not being able to open the links this is just guessing and hopefully giving you some quick ideas to try:) Maybe someone who can actually view the links is able to help better.
Also, this might be helpful to you: