The pilot bearing is mounted in the end of the crankshaft. When the clutch is engaged (transmission spinning), it's not moving at all - or rather, both sides are spinning at exactly the same speed. When the clutch is disengaged (transmission not spinning) is when there's rotation there, same as with the TOB.
If light pressure on the clutch pedal changes anything, the issue is definitely with the TOB, in any case. The clutch would have to be disengaged for the transmission input shaft bearing or pilot bearing to see a change in their operation compared to when it's engaged, and light pressure isn't going to fully disengage the clutch, only start to press the TOB against the pressure plate fingers.