Hi Anthony,
The issue you're experiencing maybe a software-related. In order to fix this issue, let's do some troubleshooting steps.
Run the Surface Diagnostic Toolkit (SDT)
The first step we need to do is to run SDT which checks your device for any drivers that needs to be updated. Sometimes, the lagging and pressure detection maybe due to lacking drivers that needs to be installed in order for the application or software to recognize the pen. To find out more information and steps on how to run SDT, simply click on this link.
Run the Pressure Sensitivity Test from your Surface App
Surface has its own application where you can run the pressure sensitivity test. After running SDT, we would suggest that you run the pressure sensitivity test on your pen to check if you would need to adjust the sensitivity. Once you're in the app, just click on the "Pen" icon and follow the instructions that will allow you to adjust the sensitivity and pressure of the pen.
Please let us know if the issue still persists after following these steps as more likely, if that would be the case, we may need to further troubleshoot on the issue.