Monitor turning on by itself after turning off due to Power Setting

Nothing comes to mind, unless it's MS Antimalware scanner. You could look in this folder to see when the last logged activity was (an *.log file, open with a text editor):

C:\ProgramData\Microsoft\Microsoft Antimalware\Support\

Have you tried leaving Task Manager open, on the processes tab, and sorted by the CPU % column to see if anything is using an unexpected amount of processor time when the monitor comes on?

Have you tried unplugging the mouse, in case it's randomly getting some stray light bounce direction and waking the system up?

Does it happen at exactly the same time every day or day of the week? How often is it happening? I am getting the impression that this is something waiting for a PC idle state instead, yes?

Does it happen at exactly the same time every day or day of the week? How often is it happening? I am getting the impression that this is something waiting for a PC idle state instead, yes?

It happens whenever the PC monitor turns off. It seems to b the same amount of time after the screen initially turns off, I'd say a minute, then the screen turns back on, then there is another 3 minute delay (thats how long I have ths screen pff time set), then it will stay off until I move the mouse again

I will try the task manager trick