I too am having this same issue recently. I don’t know if it was since the last update as I only noticed it a couple days ago but I suspect it was. I will set it to my GPU intel arc b580, and on restart it reverts to auto. I tested restarting the server and that stays as my gpu, its only when my PC restarts which I have it set to do nightly at 4am. Super annoying.
Yep it happens to me too, running the latest Windows 11, latest Plex, and latest intel drivers. I want it to use my Arc A380 as a dedicated GPU transcoder but everytime I reboot my HTPC it simply resets back to auto. It’s incredibly frustrating.
Now another issue! Went travelling and brought my trusty chromecast. No options to transcode, super frustrating! Buffering every couple mins and major annoyed kids! What the hell is up with Plex lately!
Chromecast follows the parameters of the device that initiates it, so if you need to change quality, you need to change the settings in the app on the device.