Question Black screen for 2 seconds, only on first boot ?

[Mitrill]

Hi, i have a strange issue with my PC, and I can't figure out if it's the PC or the Monitor itself.
Only on first boot, after about 5-10 minutes the main screen only (I got 2 screens) goes black for like 2 seconds, then it turns back normally.

This not happens untill the next day or untill i leave the computer shut off for a while.
If I restart the PC after that happened, it doesn't occur. Seems like that it doesn't happen with my old pc attached.

I use Display Port on main screen and HDMI on secondary. I also changed MOBO today, but this still happens.
P.S. I don't hear any device attach-detach sound (like if I detach the cable) or i don't have any error on windows registry about video drivers

Does anyone had same issue?

PC SPECS
MOBO: B760m Gaming X AX DDR4
CPU: Intel i7 12700KF
GPU: RTX 3070TI MSI
PSU: Corsair RM750e
RAM: Corsair VENGEANCE RGB PRO DDR4 32 GB
MONITOR: KOORUI 2K 170Hz

 

[NanoSuit3]

A while ago I had this same thing but it did not bother me at all until fully upgrading to a whole new Generation of hardware where after turning on my streaming PC it does that same exact thing BUT only cuz it has to identify the system to it's Capture Card. I preferred the way it was back before upgrading fully but this seems like it's a normal thing as it's probably just reidentifying the signals strength on the display or displays..........................