No falldamage if spamming Spacebar

Dear Mojang Team,

I dont know if I am an Idiot but when I am falling down a hill (just falling, not jumping down), and spamming my spacebar so that I jump at the moment I fall on the ground I get sometimes no fall damage, I tested it multiple times in different Worlds so I hope this will be fixed. ( Sorry for the bad English, I am German )
I do have a Video Proof https://youtu.be/LxJlGLncUNE

Edit: I tested it a few times and it seems to be still and issue, but its not everytime and just happens unfrequently.