Have now been to Suoerchargers on 2 separate occasions. Maximum 48KW is unacceptable!!!
It depends on your state of charge (SOC). You might only get 25 kW if at 90% SOC. Cold temps also reduce charging speed until the battery heats up.
It might be worth reading this article: https://teslatap.com/articles/supercharger-superguide/ which explains how it works.
Also the battery size matters. If you have an older X60/75, they will never get more than 105 kW.