This relies on the CPU's onboard graphics processor. There are a couple of reasons to switch back to integrated graphics from your dedicated GPU. The first is if you are getting rid of the GPU.

Switch to onboard graphics Since the GPU is not working, you'll need to look for an alternate way to send the display signals to the monitor.

On Apple's latest MacBook Pro systems, the dual GPU setup allows for dynamic switching between the onboard and discrete graphics chips to optimize performance and battery life, depending on the ...

Both monitor and TV are plugged into the GPU. If the motherboard is only outputting to the onboard video, I can remote in but I can't, AFAICT, tell it to switch adapters.