Hi,
Sorry, the version I placed in the previous message was the web player version. As of PMS version 1.20.3.3421-54b6523bd it worked for me. Yesterday removed/re-added the DVR to setup the new EPG support for my country. Currently I’m also on the same version as you and no issues there for me.
Try installing the latest WinTV (this also includes the latest drivers):
If that doesn’t work, manually uninstall the Hauppauge drivers, uninstall WinTV and install the driver only (https://hauppauge.s3.amazonaws.com/drivers/wintv-solo_dual_quadhd_5_2020_0406_38125.exe). Although on my side it works just fine with the drivers in the WinTV package (and WinTV also installed).
Does DVR work at all when using it in WinTV?