My SONOS Move battery will not charge via USB-C port on the back. This is the first time I have tried to charge it away from home (and away from the charge base). Much to my disappointment, none of the USB-C chargers I (or any of my friends) travel with seem to deliver any charge to the battery (which is now dead). I have tried two chargers that both output 15V/3A, which meets SONOS spec. It could be a faulty port? Any advice or guidance would be appreciated.