iPhone not charging from BMW music-media-adapter ("y cable")
I drive a MINI Cooper (MINI is made by BMW), and the BMW music-media adapter (model 61 12 2408012, the "y cable") that I use to connect my phone to my car stereo has recently stopped charging my phone. I have an iPhone 12 mini. The adapter cable is made by BMW specifically for Apple products.
I have ruled out the adapter itself or my car by (1) buying a new adapter and (2) realizing that the old and new adapters do not charge my phone even when I plug them into an outlet in my house.
When my phone is plugged into the adapter, it acts like it is charging. The battery is green and there is a lightning bolt on it. But my battery percentage steadily goes down instead of up.
Do any other MINI or BMW drivers have this issue? Any advice on how to fix it?
Workarounds for other ways to connect my phone to my car (which predates CarPlay) would also be appreciated.
iPhone 12 mini