I turned the surge protection off yesterday after one shutdown. After that no shutdowns but one "flash" or snap (was like electric shock) where my screens went black for couple of milliseconds. That can't be good for my system so I will most definitely contact supplier to get this PSU changed.
Edit: Turning off surge protection does not help. Only way is to unplug PC from AC, just slightly move connectors in PSU and plug in AC. After that it works some time, very weird, absolutely no idea what could fix that.