No my power supply is definitely clean, I have no issues with other larger appliances at all.
I used DDU, so I'll try and replicate those conditions after work where I knew the crash was coming (game on monitor, Firefox and YouTube on other). Not using any adapters at all. The 60hz display is direct HDMI to HDMI and the 144hz is DP to DP.
I think the worst case scenario is that it is somehow the GPU and GPU driver and I'll have to switch to Nvidia