Hello @Rolig Loon, thanks for such a prompt reply.
I totally understand I should arrive at the TP location; the problem is that that does not happen all the time - hence the question. In general, we use stores' (or other regions) landmarks to teleport and as often as not, I arrive at groundlevel regardless of the LM - my love uses it at the same time and she always arrives at the correct spot.
While I use coordinates to move around on her land (usually when we're decorating) I've never done so teleporting from region to region - so it's a bit odd, then.
Thanks.