Sorry to hear that.
But I guess misery loves company.
I suspect that there is a very slight mismatch in the tooth profiles between the metal motor gear and the plastic output shaft gear.
Maybe they will wear in after heavy usage, I don't know.
I have looked at purchasing a high quality nylon replacement gear from McMaster-Carr
It isn't even particularly expensive, but it will require some careful lathe work to adapt to the shaft.
I have a lathe but that won't help others who don't (I can't volunteer to make a bunch of them, sorry).
However, notice the 14-1/2 degree pressure angle.
Chances are this is where the problem is.
The reason I was bothering to look into that to begin with is that as-shipped the plastic gear on mine also wobbled.
Clearly there was too tight of an interference fit between the plastic and metal parts which mushed out the plastic.
So I pressed it off the metal shaft, re-bored the gear hole slightly larger for a light press fit and pressed it back on.
Wobble gone..... clicking remains (was there from the start).
Unfortunately the gear pitch is way to fine to print a replacement (at least it is too fine for my printer).
But I could press on a flat nylon disk and hob the teeth.
That's a lot of effort though.
It would probably be easier to fabricate a tiny belt system to replace the motor and output shaft gears.