I didn't want to file a bug report quite yet, but I found it humorous my hornet decided to fly around in space. I wondered why they weren't attacking that unit until I scrolled over and saw it was much much too high. Hilarious bug.
I get the same thing on metal planets. Its an old bug that was fixed as far as I knew. Looks like its back now. I have a screenshot of regular planes, then orbital units, then orbital planes. The orbital planes are about where the orbital units SHOULD be, but right now they're so close you have a hard time differentiating them from planes.