intermittent throttle position % drifting - doesn't follow TPS V

Trying to get my van systems dialed in and running well, before starting to log data.

The system occasionally, reports a throttle position % that doesn't follow the TPS Voltage. The throttle position can drift upwards.


Here's a video of this happening, while engine is off, and key is on, with some of my tapping on the sensor, and moving the throttle shaft by hand. At the end of the video, the TPS V is .5V, but the throttle position % reported by TP5, is over 7%.
https://youtu.be/qaS7B4cauSM

Any ideas what could cause this? Could this be caused by faulty calculation in the ECM or a faulty memory address location?