Weirdness with teleporters in forge?

Been trying to figure this out because it's handicapping an idea that I have. First the idea: I have a small map where one base has only three points of entry, all on the same side (so fairly easy to cover). I want to add a teleport receiver in the back, and the sender node would be on the other side of the map. But I'm doing funny things with the setup because I want it to take a while to get from point A to point B, and I don't want it to look like a conventional teleporter. Without going into all the specifics (hopefully the map will be posted here eventually) I want to have the sender node inside a tube or tunnel, with a grav lift or man cannon forcing the player into the teleporter - either above his head or around a corner, something like that.

The problem: the sender is working really inconsistently. Sometimes it just flat doesn't work. I've had it suspended in the air, sitting on the ground, and suspended but sideways or upside down, and in all cases it seems to work sometimes and not others. I have no idea why. I tried increasing the radius of it and that didn't seem to help. What is going on? Is it just something weird with forge? I have to admit, I didn't go into custom games to try it out. I did notice though that at times it seemed like it wouldn't work when I was in spartan mode, but then it DID work when I was in monitor mode. Yet in both cases it was on the same channel (alpha) and the teleporter did appear to be active. I thought maybe it was because I was flying through it at grav lift speed, but then I sat it on the ground for testing and it still didn't work. I don't get it.

Added after 1:

As I posted this, I had a thought. My receiver node was in a weird place, up inside a little structure I made. Is it possible it was too close to the ceiling and my spartan model just wouldn't fit, so therefore it just wouldn't teleport me?

 

I think I may have it figured out - I'm going to check out my theory tonight.