No idea, just a couple of WAGs...
1. Any chance there are multiple profiles defined and driving/app are not the same? FSD beta safety score should follow the car, not the driver, but perhaps the car is logging the miles under a different account/profile than the app is showing??? Has the car been under the same account since day 0? Or did you transfer a reservation or it is a used car and something never got fully pushed over to your current?
2. Also how good is the WiFi signal? Any issues with that before? Getting regular updates via same parking location and WiFi? The car is supposed to upload driving score data after put into park. If WiFi is not good, could that data never actually get pushed up to the mothership?
Good luck with it. I gave up on getting into that program, got tired of getting dinged for turning too hard or having others jump in ahead of me and my following distance was unsafe. Next to impossible in normal traffic and where I have to drive around here not to get dinged. Plus I got tired of driving like a 90 year old hypermiling in a Prius, life is too short for that.