My PitchFactor was doing the same thing. If you contact Eventide, they will tell you how to fix it. Here is an analogy of the problem:
When headphones are not plugged in all the way, you usually only get sound on one side with some cutting “in and out” on the other side. Pushing the headphone connector all the way in, fixes the problem. The headphones were never broken, but they were not plugged in all the way. This is essentially what is happening with your TimeFactor. There is a ribbon cable inside that simply needs to be plugged in all the way.
I fixed my PitchFactor once I understood what needed to be done. It is not hard. If you have ever changed batteries in an electronic device or used headphones, you are fully qualified to fix your TimeFactor. Again, it is not hard.