Conquere

I'm using AOC C24G1 as a main display and Philips V-line 243V7QDAB/00 as a second display for about one and a half of year. I was using only AOC for a while, and few weeks ago i've connected philips back. Now main display is getting black screens for about 2-5 seconds every few hours. I tried reinstalling display drivers, turning off adaptive sync, changing display port cables and nothing helped. What could be a reason of that?