I have removed another card, not the one that's currently crashing.

The card was working without issues until now ( I changed its thermal pads 1 month ago and ever since then it was working super fine)
The riser is fine, at least not showing any problems. All cables are done right.

I have uninstalled my drivers with DDU and installed the newest ones via the GeForce experience.

I read in a forum that this may happen due to increased OC - so I lowered from +850mhz on the memory to +800 and will keep an eye on it for now.