My mac mini m2 keep waking up or showing no signal on external monitor

So when I put it to sleep doesn't matter if auto or manually it shows no signal after time on my monitor and it's blasting at night which is annoying. I've turned off all settings in a power saving settings, also rode many articles and couldn't find solution. While checking on activity monitor only window server is preventing sleep. By the way I use iiyama monitor connected via usb c to display port. Selected processes indicate as preventing sleep yes, and also SharingD sometimes and user activity.