Be sure to file a bug report so that it can be fixed. In the mean time try using FaceTrackNoIR V200, I’ve been using it for almost 3 months and it hasn’t lost the settings for me. The manual page for Curves explains how to tweak the sensitivities.
Be sure to file a bug report so that it can be fixed. Also post your problem in this thread(and vote for it too): Tobii Eye Tracking needs configuration options. In the mean time try using FaceTrackNoIR V200 as Hester40MT reported that it works with the Tobii 4C:
Just be aware though in his screenshot he had Smoothing set to 20, I’m not sure if that was the default or if he changed it but having a smoothing that high will probably lag a little (Filters: The higher the value, the slower the response). The default smoothing for my Tobii Eye Tracker 5 was 1 so try that first and increase it later.