that's strange, i used to have this issue all the time when i first got the car but haven't had it happen in a few weeks now...tons of other issues, but this one in particular seems to have gone away. apparently not for everyone, though...
I haven't seen this issue in a while either. My first month of ownership, too many times after unlocking the door and sitting in the driver's seat, it would ask for the key card. Reading this made me realize that hasn't happened in a few months--actually also around the time my trunk started unlocking reliably. A number of things have happened since then, including multiple firmware updates, app updates, Android patches specifically aimed at improving BLE connectivity, and a whole new version of Android (Pie).
It proves that improvement over time is possible and I hope they keep working toward increased reliability. I will say I'm much happier with the phone key now than I was after taking delivery in the spring.