When a schedule is created for a drop off, there is only a temp stop created for the provider station, but not for the requestor that is on the other side of the space elevator. This does not happen when the requestor is on the same surface as the provider, i.e. a temp stop is also created.

Currently installed: Factorio 2.0.76 / SE 0.754 / multiple versions of LTN tested (2.51, 2.6, 2.71)

For anyone else stuck on this, the solution is to switch to this new mod.

https://mods.factorio.com/mod/ltn-space-exploration

Glad I didn't have to give all my stations random unique names!