Automatic Graphics Switching

Certain MacBook Pro models come equipped with two graphics card, one integrated into the Intel CPU while the second is a discrete GPU with its own dedicated video memory. On all recent models of MacBook Pro, this graphics card is made by AMD. macOS is designed to automatically switch your workload from one card to the other to save battery life.

Depending on the issue you are trying to diagnose, You may have to switch Automatic Graphics Switching on or off:

1) Open System Preferences and select the "Energy Saver" section:

2) Click the checkbox named "Automatic graphics switching" to turn this feature on or off: