My jump is like getting stopped by an invisible block or something + Blocks disappearing when speedbridging too fast

[Tsonggo]

So like for example when I do a 3 block jump or whatever something is like stopping me like a block or something. This bug has been around for a while.

Also when I speedbridge too fast my blocks disappear.

 

[Lionelmine]

Why are people in this post using the full form instead of the short form?