I tried turning off GPU tracking, but sadly no luck. I double checked that the track layers have the gear on.
Weirdly, when I open a project that was tracked on a different computer, I can go into Mocha VR and edit the horizon line as normal, however if I start the project on my main rig, the horizon line will never curve, it will just shift around as a straight line. I've tried this with three different shots and they all track great, but the reorient tool won't work for me (unless I create the project on a different system first).
The two systems I work from are almost identical, except one has a GTX 1080 for a GPU, while the main rig (the one having issues) uses a GTX 980ti. Both machines are running Windows 10.