Really sorry for my language.

If i can i explain this more clearly.

Few days ago I get power outage.
Pc was running in fire strike benchmark with monitor ON.
At the same time my mother was powering on electric oven in kitchen.
And then power went out in house.
Just before power went out, pc was running in Fire Strike test, and monitor was on. When power went out,pc goes off and monitor goes off. When power back ,monitor turns on itself .

Then I booted pc , all was looking fine, Windows 10 booted with 144hz .

But after moment I shutdown pc by clicking shutdown in Windows 10 and I manually turned off monitor.

After 30 minutes ,first I turn on manually monitor,then I boot pc again second time. Windows 10 booted with lower refresh than 144hz.( on nvidia panel still 144hz ) .

To restore 144hz I just turned off monitor and turn on again. And this not happened since.

And my question. It was related to this power outage or just coincidence?

And I am not able to reproduce. Turning off pc few times and booting again,and nothing,still 144hz. Even I cut power 3 times to check,but still 144hz on boot.
I cut power to pc few times to reproduce issue exactly like on this day. But i cant reproduce. Pc booting and restarting exactly with 144hz.

So why it happened just once? Can somebody explain me? Something related to outage or just random glitch?

So maybe that was,system,drivers or something but not related to that power outage? Or maybe power outage was the reason, but the problem didn´t show up immediately?

My pc: *
Asus Z170-P with 6700K cpu
Corsair 750 RM
Gtx 1080 Ti Founder Edition
*Monitor Red Eagle IIyama 24' 1080p 144hz plugged by display port cable to GFX.