When the monitor of your macOS alway frozen

Reset SMC or PRAM/NVRAM could helps.

In my data point, the second solution works for my MacBook Pro (15-inch, 2018).

How to reset SMC

Keep power on (using external power)

Complete shutdown you computer (shutdown instead of restart)

Press the [left-side Shift]+Control+Option keys, along with the power button on at the same time.

Release all of the keyboard keys at the same time, including the power button.

Turn On

How to reset PRAM/NVRAM

Keep power on (using external power)

Complete shutdown you computer (shutdown instead of restart)

Turn on your Mac using the power button.

Press and hold the Command (⌘), Option, P, and R keys on your keyboard at the same time as soon as you hear your Mac’s startup chime sound.

Wait for a few time

Release keys