It's entirely possible your headphones could be faulty. No setting should be changed for your headphones to be recognized and working.

Also bear in mind GrapheneOS prevents new USB peripherals when the device is locked, by default - meaning that plugging in your headphones without unlocking the device first won't work. The team is aware the UX around this isn't the greatest (for instance, iOS shows a notification telling the device won't work unless you unlock the device) and could be improved in the future.

4 months later

Finally Bluetooth headphones work reliable for me in the secondary user profile!!! Yay! Thank you GOS and or Google for making it happen 😸

18 days later

I've tried buying a cheap generic USB adapter for audio jack, but that got rejected by the phone, it said it could not connect to it, but could tell me that it was an audio device. When I bought a Samsung one it worked fine.

To test if your headphone is faulty or not plug in into a few other phones and other devices (laptops). If both channels work there then your headphone is ok, and if the same thing happens everywhere then its faulty.

Drivers are important. USB headphones use drivers. If the driver is not installed on the platform the device wont work. Less known devices may not have their drivers installed inside of android OS. Generally device makers make sure they submit their drivers so they are available on platforms otherwise it will affect their sales big time.

I often find original Google USB-C earphones not working in a secondary user profile. I plug them when phone is unlocked, nothing happens, built-in mic and speaker are used. Anyone knows what's up with that?

2 years later

rkeenan I have tried few pairs of USBC headphones with my pixel/ graphene phone and I have the exact same issue. Someone posted somewhere a pair of headphones that worked well, but can't find the post now.

      Bdesign

      Not sure if it was my comment but ive never had a issue with the Samsung EO-IC100BWEGEU for the white ones, or EO-IC100BBEGEU is the black versions i also know work.

      Never had a issue with ether ones of those but those are all eu versions. i know samsung has US versions of those too and they might be differently so be careful checking product numbers if you decide pick up IC100's

      Overall I'm very happy with how they sound and their balancing and pick up a bunch when they are on sale as ive found nothing better around the 15 dollar range