Refresh rate
Adjust how frequently your screen is redrawn. If the rate is too low, your screen may appear to flicker. If the rate is too high, the screen may be black because it doesn’t support that rate. Check the documentation that came with your display for the best rate. If you have a supported display, you can set your display to dynamically adjust its refresh rate, using Use Night Shift.
Detect Displays
Scan for all the displays connected to your Mac. Press and hold the Option key to make this button appear in place of the Night Shift button, then click Detect Displays if your Mac doesn’t recognize a display you just connected.