Modern Vespa

Hello all! I'm trying to figure out a ticking/clicking sound coming from the rear of the scooter. The click was first noticed after the rear tire had gone flat and was replaced (picked up a nail or something on the road). I did find some forum posts to try some troubleshooting, but the click persists. So far I have tried:

-Bearing located on swing arm replaced
-Drive belt and rollers/shoes replaced
-Rear Hub oil replaced
-Brake rotor/pads inspected for high spots, none present
-Tire is brand new, nothing embedded, and nothing rubbing
-Engine oil and filter replaced (probably not relevant, but it was part of recent maintenance around the time the click was first noticed)

A video of the sound can be found here:

https://youtube.com/shorts/fX0P1YrilU4

It doesn't always happen when it is on the center stand, but usually only after it's been in motion for some time. When in motion, the ticking also matches the scooter speed (faster speed, faster clicks; slower speed, slower clicks). It also only occurs with the wheel on, spinning the rear axel by hand does not produce the sound, nor does spinning the belt by "hand". Even when I inspected the clutch assembly during the belt replacement and tested the bearings there, no noise.

It is beginning to drive me insane trying to figure out what the problem is (or even if it is a problem, and it's just a noise that will go away on its own as new parts are broken in). Any tips will be greatly appreciated.

its just the shaft gripping the sprocket that turns the clutchshaft

So in other words, a completely benign sound that isn't actually a problem, and I've been going insane over nothing?

Welcome to the asylum.