You tried a belt.
The noise happens when the belt is installed and properly tensioned on the drive pulley.
It is not unusual for the large pulley to wear, doing so in the center splines that grip the spinner shaft. It also could be the early signs of bearing failure. My suggstion is to wait and see what happens next. If it is indeed a motor issue, you'll know in a few weeks or so.Same if it's a bearing.