I am having issue setting my 2nd monitor as the Presentation Device.
My speculation is that both of my video output device names are empty (see screenshot), which creates a conflict for the preference to remember which device was selected to be the Presentation Device. The “Use as Presentation Device” checkbox value stays checked on all Output Devices.
I have tried deleting the user preference, still no luck in getting the device names registered. I tested on an older Intel MBP with the same setup and it worked, if this piece of info helps.
Macbook Pro 14" 2021
External Display: Dell 2720Q via thunderbolt