/tp doesn't work while you are in a minecart or a boat. The console will say "Teleported (player) to (coordinates)" but you won't go anywhere. Getting out doesn't cause you to move either.
Related issues
Comments
CubeTheThird
Does this also happen when in a boat?
I'll get to that.
Yes it does.
Confirmed for boats also.
Duplicate of MC-16.
Can confirm.