Partnership withholding question for K-1

I received a K-1 for a firm I was a partner at for part of 2023. The firm/partnership is located in Illinois, but I am a resident of another state. It is my understanding that the partnership is supposed to pay the withholding tax in Illinois for all partners who are non-residents and show this on Section 7 of the K-1-P that comes with my K-1.

I also have confirmed with the IL DOR that partnerships are supposed to pay the withholding for any period of time one was a partner at the partnership.

This firm refuses to pay the withholding saying that because I am no longer at the partnership they are unable to deduct it from my earnings, so they will not be paying it. Withholdings have never been deducted from my earnings in the past. And I was a partner during the time that the K-1 is for.

Has anyone else had this happen or do you have any insight? I appreciate any information. Thank you!

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