When create a new world, player bobs in and out of ground therefore being unable to move

When you spawn in a new world you (player) get stuck on the ground bobbing up and down not able to move

What I expected to happen was...:
The player to be still not glitching through the ground

What actually happened was...:
glitched through the ground

Steps to Reproduce:
1. open minecraft
2. create new world
3. you stand there glitching through the world