like other folks said, make sure you have a 60 AMP breaker in your electrical panel for your wiring and also check if your rivian is set to accept 48 AMP charging, I had a similar issue, it was cause the Rivian settings were set to 32 AMPs.
So not sure if this is the right forum for this question, but I have a bourgerv charger 48 amps, i used to use my Audi charger on the Rivian, but that was somewhere around 32-40 amps, so I was getting 7kwh, with the 48 amp I'm expecting 11kwh, the rivian down grades the amps from 48 to 29 and...