If you place your translocator on top of payload, the translocator follows the payload. But when you press e to teleport to it, you instead go to original position of where the translocator were, even though it has moved.
I tried it and used the highlight feature to capture it:
A while ago I and @Mesonnaise tested on the Problem TL has to do this. We first were aware of it being possible on moving platform where it can be used as an Exploit:
Then we went on to Payloads:
So the Reason why this happens is that for some reason on some locations/Positions (Sometimes after the Moving Object changes directions or starts/Stops moving) Translocator get’s “tagged as Unsafe” (So the game thinks its on a Spot where it can’t Translocate) So in order to prevent an error it takes it’s last Save spot and places you there. You can visually see this sometimes on the payload when the Translocator itself stays at said Save spot and just flies in the Air.
You can abuse this and another bug to create one of the most broken things ever to have existed:
If you want to know more Sombra bugs to help you staying Save I have a post with all that I found since 1.26: Even more Sombra Bugs in 1.26/1.27/1.28 [With Video's]
Ps: You may want to change your Title because most people will just think is the TL into Payload but instead of the very unknown you found and will ignore it.