Teleporting a player who is falling at terminal velocity, does not correctly preserve momentum. It has a jarring rubber-band effect on the y axis.
eg.
"tp @p ~ ~100 ~" performed while falling at maximum speed, will tp you to y+100 preserving falling speed, then 1 second later tp you back to y+100 without momentum to begin falling again.
Expected behavior would be a tp to y+100 preserving falling speed, one time only.
Related issues
Comments
edited description to include an example command, but it happens in any vertical tp command.

Sounds related to or duplicate of MC-44823
Please provide the command used to teleport.