Sudden FPS crashes and Monitors turning off

Since a few weeks im experiencing sudden fps drops while playing valorant. Its dropping from stable 144Hz to 20 slowly decreasing to 1. When i try to tab outside the game all my 3 monitors lose signal (they turn grey and start searching for signal without success). After restarting my PC all works fine (At least for about a day).
Do you know what may be causing that or how to find out?

My Setup:
Intel® Core™ i5-8600K
Palit GeForce GTX 1060 DUAL
G.Skill DIMM 16GB DDR4-3200 Kit
ASUS PRIME B360-PLUS
be quiet! Straight Power 10 500W CM

2 Monitors connected with display port, 1 with hdmi

The setup is actually about 3.5 years old (and yes im aware that i messed up the parts selection back in the days).