Addding platform behavior to the solid block was just an easy way to make it move back and forth
I tried to play a bit around with the example.
If i change the code that change the angle of the solid to not run every tick. I can not provoke not beeing able to jump. So it is the change angle and rorate that happens just before the player actions that makes the player think its not on the ground.
But the lower interval the more often it happens... So the problem is not solved. Its just harder to hit the right timing....