Display set to turn off but turns on again immediately.

2 months ago i bought a new PC with windows 10. Everything runs perfectly, except this annoying thing:

I have display turn-off set to 15 minutes. So after 15 minutes of inactivity the display turns off, but then turns on immediately again. After an additional 15 minutes the display turns off and stays off (and eventually the PC goes into sleep after 30 minutes). It only does this the first time after a reboot/wake up from sleep. It does it irrespective of open programs/apps.

Is there a way to find out what is triggering the display to turn on?

Edit: It's most likely not the mouse nor keyboard as these were used on my previous PC (WIN 7) without this problem.

I had a similar issue previously and I think that was something to do with Windows 10 itself and the touchpad/mouse. Bear in mind that windows 10 has tones of additional background behaviours which often interfere with what we usually do with PCs. Some of the services may want to keep your PC running and would interrupt idling here and there occassionally. Sometime, it would be mouse or touchpad issue that they are sensative to any slight vibration on your desk which may interrupt the screen protector as well. In either of the case, I had mine solved by disabling mouse/touchpad and cutting off network/windows unnecessary services when I am not using computers generally.