2013 850 touring belt question

I have an 850 touring. After about 3 years of pushing around rock and snow the belt started to slip. I went to the dealer to get a belt and noticed the original belt number was 3211123 but had been changed to 3211160 . When I went to swap them the new belt was thicker . I figured it’s a heavy duty version so no problem . Ever since I put the belt on its hard to shift. Shifts great in park with motor off, shifts good when you start it and out of park . After that shifts hard. If I turn it off it shifts easy again. Pulled the belt cover off and when you first start it the belt doesn’t turn. Once you power it up the belt engages but never stops spinning even when you put it back in park and let it idle. I think that’s why it’s harder to shift.
Anyone run into this problem?
If I have to run this wider belt what adjustment do I need to make to the clutch to get it work right ?