Hello coltonhill,
Welcome to Microsoft Community.
After fully reading everything you've posted here, I judge that your Surface Pro 9's screen should not be malfunctioning (unless you notice that you can't touch with your fingers when the Surface Pen won't operate on the screen), and it's pretty much a malfunctioning Slim Pen 2 nib.
However, if you are replacing a worn nib that is not stable enough to be used as a test sample, we recommend that you try to replace the nib under warranty by following the instructions in the support link below:
Replace Surface Pen tips - Microsoft Support
After replacing the new nib, test again to see if this problem will be improved.
Best Regards,
Mitchell | Microsoft Community Support Specialist