Erratic paddle performance
When using any touch paddle product, be sure you have a good grounded station. Stray RF will can cause self or erratic keying, especially with end fed antennas or any antenna in close proximity.
What could be happening is the cable from the touch paddle product, going to your rig, can be acting as an RF counterpoise from the RF currents coming down the feed line to the radio and into the sense circuits of the touch paddle product. This may result in erratic performance.
To cure this, just lay out an RF counterpoise wire on the ground (or around the room) about 1/4 wavelengths long (see below) and connect it to the radio chassis. The radio will be at a natural zero point for RF currents.
Of course proper station grounding is vital to good performance. A 1/4 wave counterpoise, for the operating frequency, will substantially help with RF issues if you cannot ground your station.