Hi. Fast question. Today after quitting fire strike ( 1920x1080 res ) ( i quit after 10 second test ) i get weird single flicker on desktop,like here:

It happened just once and one single time,but i want to be sure that card is ok. It flickered maybe 8 seconds after quitted test,on desktop. I tried to reproduce but i cant.
I tried, tried and i tried running fire strike and immediately closing,all full 3 days. Still cant reproduce it. So i dont know why it happened once.
No overclock,no artifacts in games. Just single flicker in desktop after quitting fire strike. Happened after 15 seconds after closing fire strike in desktop. I am not able to reproduce now. So why it flickered?

Monitor is GB2488HSU 144HZ IIyama. Thanks Desktop is 1920x1080 144hz. Drivers 378.92
Card is 1080 Ti , no OC ,stock.