Teleporting player with relative cordinates teleports relatively to player instead of relatively to command execution place (bug is for: command block, command block minecart and for execute comand).
Teleporting other entities works as intended as Searge told in MC-102598
Linked issues
Comments 3
Post that on MC-102740, you didn't provide the command, so I assumed you used execute on the player.
Please use the search function in the future.
Also execute is intended.