My Mac Mini (2020) keeps shutting off

Are you sure that before starting the computer that the power cord is snugly in the port?

Are you sure that your surge protector that you are using doesn't have any damaged ports?

Are you sure that there isn't any sign of fraying on either cord?

If it shutting off while you are gone, did you check the Energy Saver settings for shut down?

Are there any background tasks that might need to shut down when done?

Does the computer wake up by hitting a few keys on the keyboard? If that's the case, the machine has simply gone to sleep.

Are you connecting any third party USB devices to the computer while setting up Energy Saver to run? Low powered mode can cause indiscriminate crashes preventing wake up if the device connected is not familiar with Energy Saver low power mode. Putting hard drives to sleep in the Energy Saver settings can trigger this a lot. If you are concerned about power consumption, use Screen Saver instead of Energy Saver if you have to leave those devices connected.

If you have older electricity in the building, the circuit might be shutting off due to power overload, or water intrusion on ground fault interrupt switches. This can also be triggered by running vacuum cleaners when there is excess power load. Talk to an electrician to ensure you aren't overloading your circuits.