I just upgraded to a 2019 Cx-5 from my 2014. The Android Auto USB port doesn't charge my Honor 8 phone, it just keeps it at the same battery percentage +/- 1 percent over an hour of being plugged in. The other port right next to the Android Auto port charges my phone about as fast as a wall charger and so do the two in the backseat.
Does your port actually charge your phone?
Does your port actually charge your phone?