In the settings for my “DESKTOP-NHKFVUQ” I can select a hardware transcoding device - either “auto” or my 2080 TI. However, the option appears to be missing completely from setting when I switch to my NAS. I’ve got a Quadro T1000 8gb in QTS mode, drivers installed and everything green-lit on the NAS (so it appears) but there’s no option to select a transcoding device.
If that’s from the Qnap app store then you want to get rid of that and install a more up to date version by downloading direct from Plex and installing manually instead.
Ah! So it was just that QNAP’s latest PLEX update is 11 iterations past-due. I kinda figured that might be it when I was browsing the forums for a solution and noticed others were well past 1.3 - and now I recall having to manually install an updated version the first time I set up my old NAS.