Plex did have a problem with the “Plex Tuner Service.exe” that you corrected with the PMS upgrade. There is nothing that can be done if the Device identifies itself to Plex incorrectly.
Hauppauge has a program to clean up drivers and configuration before you reinstall the drivers: Hauppauge Support | Support Utilities: HCWClear and Prodinfo. You can also identify the product.
After you clear and install if you still have a problem grab the logs after you try to setup the DVR: Server Settings → Troubleshooting > Download Logs. Drag and drop them in a reply here.
