Yeah it is a problem with those.
Although most new GPUs have the revised 12v-6x6 connector, which is supposed to be much safer. I have no heard of any issues of melting with 12v-6x6. Though I still worry a bit about clearance.
The original 12VHPWR has +H on the connector:
The 12v-6x6 has ++H on the connector.
There were also different cable designs, and I believe one design was more likely to come undone under heat and that design type is no longer being used. But who knows if all AIBs or PSU brands have switched over to the better designed cables.
Someone correct me if I am wrong.
I believe the problem is more likely to occur on the 4090/4080 as well due to higher power usage?