you are unable to instantly jump when a jump is near the maximum jump height.

[scnoobi]

this is an edge case.fyi:P

when you land on the edge of an object its unlikely for the person to instantly be able to jump again even if they are holding down the jump button.

reproduction:
go to the gym level and go to the crouch jump max height block.
do a crouch jump onto the block and you'll see that you will not be able to immediatly jump again