Smart battery case not charging phone
I have a nearly new iPhone Xs Max, which I bought with an Apple "smart battery" case. I have noticed on several occasions that the phone battery would drain to the point of giving me a low battery warning while the external battery was fully charged, and at other times the phone wold remain fully charged while the external battery drained. Today my phone battery ran out completely ([hone died, and gave me he dead=battery icon when I tried to restart it) while I was sure the external battery was fully charged. I plugged the whole thing into USN charger, and after a few minutes the phone came back to life. Battery level was indicated as iPhone 2%, smart battery 96%. I find myself wondering why I bought the smart battery case if it isn't going to keep my phone alive.
Is anybody else seeing this problem? has Apple provided any assistance?
iPhone XS