So I was mapping the other day and I had to give the player this particular effect:
/effect @p jump_boost 30 200
This command basically makes the player unable to jump
After doing that I jumped on a bed/slimeblock and I jumped... the player got pushed into the air and flew 100 meters into the sky!
The more time you stand on the slimeblock/bed the more blocks you'll travel upwards when you press space (it's kinda like the boat on a slimeblock bug in 1.9)
That's it, I don't know if it is actually a bug, because to make it happen you have to give yourself an unusual effect, but still I wanted to report it to you