I picked up my new X5 here in the US in early March. I’m having this very same problem. Sometimes I have to login 2-3x a day between drives and sometimes it’ll go a few days. BMW service ensured me my system was on the most recent updates. I have Spotify premium with multiple accounts so that shouldn’t be the problem. So frustrating! Too bad too because the native BMW Spotify is so much better than the apple CarPlay version.