Someone will undoubtedly come along and correct me if I'm wrong about this, but the majority of chargers that can do both Level 1 and Level 2 are rated at a max 16A for both 120V and 240V AC; the 3.8kW figure is derived from 240V * 12A (load not allowed to be greater than 80% of circuit breaker rating--hence 16A * 80% = 12A) = 3840 watts or 3.84 kW. If I were you, unless money is no object I'd return that $995 charger ASAP if possible--there are plenty of third-party options similar to it that are available for ~$200 or so. BTW I have the same exact charger you referenced, except I bought it from Amazon for $200; did I mention that you really should return yours ASAP?
The ChargePoint Home Flex is a Level 2 charging station capable of supplying a max load of 50A at 240V (=12 kW); however, the max output will be 9.6 kW if you don't hardwire it for loads >40A. Obviously the 16A dual charger is the more affordable and/or simpler solution, especially if you live in a home where you don't have a spare NEMA 14-50 or 6-50 240V outlet or are not able to have one installed for whatever reason.
