Charger keeps tripping the GFCI on damp mornings only — is that the outlet or the EVSE?

Started a few weeks ago and only happens when it's humid or right after rain. Plugged into a NEMA 14-50 in the garage, cord and plug look fine, no visible corrosion. It trips a couple minutes into a session, resets fine once things dry out, and other days it charges all night with zero issues. Trying to figure out if I should be looking at the outlet's GFCI breaker itself or if this points to the EVSE's internal ground-fault detection being oversensitive to humidity. Anyone dealt with this before switching parts?