anyone know why you can teleport with escape now?

https://streamable.com/ikstrv

 

Think it just has something to do with hitboxes and the speed you're traveling at

 

That's just a general Minecraft glitch, nothing is perfect.
For more detail for those interested:
This "teleporting' occurs when the edge of your hitbox meets the edge of a block at speeds faster than 15bps (blocks per second). Essentially what's happening is your player model is trying to reach the other side of the block faster than the game can register the change. If everything were perfect your player model will recognise the change in a direction much faster and change to that direction instead of teleporting which currently happens.

To avoid this from happening just make sure you use your movement spells in a relatively open area. Although it doesn't really matter all too much.

Hope this helps! :)