Pitch wheel not calibrating properly

[pianimator]

The pitch wheel on my River synt, even after calibration (calibration (S-Key -> C8), doesn't always work properly.  Yesterday after several calibrations it began to work properly.  Today, upon power up, it began not working again so I calibrated and it jumps through numbers quickly while bring the pitch wheel to its extreme points.  After several calibrations, it works pitching down, but does not pitch up. Any idea how to alleviate this abnormality?  The Mod Wheel, Aftertouch, and pedal seem to calibrate properly.

[Baloran]

It sounds like a hardware issue. The potentiometer in the scroll wheel might be worn out. These are Fatar scroll wheels, which are supposed to be high-quality. The easiest solution would be to find a potentiometer that's physically identical and replace it.
Right now, I'm hesitant to send small, economy-class packages to the US—it's become an absolute nightmare. Otherwise, I can send a new knob assembly, wired if needed. In that case, there will be the cost of the part, labor, and shipping.