The tps is basically a potentiometer. The ecu measures the voltage coming from the tps & then knows the throttle position.
So yes the voltage does increase as the throttle is turned.
I suspect you didn't have the engine fully warmed up & your idle now isn't at the same rpm as when you set it last.
Try fully warming it again & resetting. Of course there'll always be minor variations in voltage & you may not get better than that
The above of course is only a very basic explanation.
Edit: don't try getting 0v after a reset, it'll never happen, you're very, very close now. I'd try to reduce it a little but not let it bother you.