This is ABSOLYTELY CRAZY.
When I play Minecraft 1.9, first time when I open a world/server It's completetly fine, but when I open a world/server again, the game goes ABSOLYTELY CRAZY. After that it is crazy with every world/server that I open. When I stop moving, it calms down a bit. When I try to move, It's insane. Only way to fix this is restart Minecraft.

Steps to Reproduce:
Open Minecraft
Open world
Exit world
Open another world