I've experienced this myself - with cablemod cable I had random black screens. It's totally gone with Seasonic cable. Mine is a bit safer, since I have watercooled card, so pcb/connector is nowhere near as hot as with air cooling.Also, melting isn't the only issue - pushing connector hard in to lock it in place in FE cards can cause connector to physically fail (as in the other video I linked) plus there are random instability issues caused by connector losing contact at times even if it's fully plugged in etc. (again video by Derbauer and other people).