There's lots that could go wrong... I don't know that there's software inside the charger, but there is inside the car which signals to the charger. There is a low current connection which is used to turn the high current connection on or off. That's done through relays that could fail. Connections themselves can fail where wires meet pins or pins meet circuit boards. If it's failed, you'd need electronic diagnostic skills to figure out which part has gone wrong - not something to be doing DIY on unless you're very comfortable with high voltage electronics.
Pretty sure this is what happened to my GE Watt Station. I would connect to the charge port, and the EVSE would show a fault. I'd power down and reset, but it would frequently take 20-30 cycles of that before the charging process began. It became gradually worse, until it was taking 30 minutes of that nonsense each time I charged. Thankfully, GE replaced the EVSE at no cost.
