The new update fixed the headphone issue with lower usb port.
I had this issue where if the headphones are connected but if the phone is idle with no music or input for headphones the phone disconnects it shows 'charging device' notification. I was getting paranoid as i was not sure if its hardware issue or software as it happened only with lower port. I dont know how but after the recent update the issue is not there..and the dongle is working like a charm. Thnx asus team. I hope the software gets updated to perfection.