I worked at an EV charger manufacturer. This is a known issue. The issue is a 240V plug value engineered for non-continuous use for things like cooking and laundry loads (where amperage spikes but levels off at fairly low amps) versus a continuous 7-10 hour load like an EV/EVSE (where you have high amps continuously and lots of resulting heat transfer).

It's limited to home EV charging. This is one reason why given the choice between a NEMA plug source or a hard wired source (to circuit in Junction box), I would choose the wired source/circuit connection.

The plug manufacturers also know about the melted NEMA connector issue and are designing versions for continuous use at the higher price points mentioned.