Heads up, the latest Catalina update caused a monitor wake issue with my Mac mini 2018. The monitor would not wake until I did a manual shutdown and restart.
The SMC manages power and hardware behavior on your Mac. This troubleshooting article explains when you should reset it, what issues it can fix, and how to perform an SMC reset depending on your Mac model (Apple Silicon, Intel with T2 chip, or older Macs)