If you constantly /tp a player, even if the specified coordinates are untouched relatives (~ ~ ~), moving around a bit will sometimes send you back to your position.
What I expected to happen was...
The player will be able to walk freely, without glitching.
What actually happened was...
The player will, if moving, glitch sometimes and teleport back to their old position.
Steps to reproduce:
1. Place on the ground a command block.
2. Put the command "tp @a ~ ~ ~" in it.
3. Put the command block on Repeating and Always Active.
4. Move around a bit.
There's probably already a report of this issue, but I couldn't find it so I created one myself.