When I connect any usb-c headphone in the bottom usb port if mu ROG 3, it just shows 'Charging via usb'....
Upper usb is absolutely fine.....
This seems to be a common problem across Android devices.
Check the PIN connection, blow off if any dirt is found. Factory reset your phone once. Check if your phone is on the latest software version.
Go to setting => System => About => Software information.
Headphones disconnecting after a few seconds for the past few weeks and since yesterday headphones not even showing ( middle jack bottom one is working fine)