Since updating my Android phone (Moto G5 plus) to Oreo (OS 8.1.0) a few days ago my phone key has started working perfectly. Prior to that it was very unreliable. It probably worked less than 50% of the time and I had been using the card key almost exclusively since late June. If you're in the same boat (that model of phone seems prone to phone key issues based on some posts I've read here), I strongly recommend trying to update the OS.
Of course, now that I've posted about it, it will probably start acting flaky again. It is also possible that some Tesla-side software update actually solved the problem. I had not tried the phone key since the recent car-side updates but prior to upgrading my phone OS.
Of course, now that I've posted about it, it will probably start acting flaky again. It is also possible that some Tesla-side software update actually solved the problem. I had not tried the phone key since the recent car-side updates but prior to upgrading my phone OS.