You need more data, and some better terminology. First, terminology. Your 120v EVSE is working, your 240v EVSE is having problems. A "fast" charger is usually a CHAdeMO charger that uses a different plug and would only be in a commercial setting. Now for the troubleshooting:
1. What kind of EVSE do you have? Are there any sort of indicators? How do they read when it fails?
2. Does your car work on another 240v EVSE? Working or not, what kind? (EIther borrow a friend's or go to a pubic charging station.)
3. Can you try another car on your home EVSE? Does it work?
4. Is there any sort of debris or obstruction in the plug or receptacle that might be hindering you getting the plug seated?
That'll do for starters.