Could be any number of things:
- Different parts, even within the same model year and trim. Even iPhones do this because they may not be able to source the number of some component they need from one vendor, and another vendor's part might be "close enough." Or in Lucid's case, maybe they ran out of stock of some part that's been discontinued and had to find a replacement. But it does create unexpected divides like this.
- Different settings, like you said. That's a very real and common problem. Each setting exponentially increases the number of combinations to test, so without very rigorous testing processes you will miss some strange and unexpected incompatibilities. Even things that don't seem like they should be in any way related, like say, one person is using built-in Spotify and that causes resource contention (memory usage, network usage, whatever) that changes the timing of some different process.
- Different history. Maybe you have a bunch of nav history that I don't and something going through that list breaks a new update. Ditto with shared contacts from your phone, call history, charging plan enrollment, WiFi networks, anything else that may change over time and varies person to person.
- Different environment. Maybe some component gets a little too hot and behaves differently in 100º weather? Maybe rough roads loosened some cable, not enough to break something completely, but bad enough that something fails 10% of the time, and the previous update didn't use that connection heavily enough for anybody to notice?
Software QA is hard.
