Whenever I call someone on Signal, we can hear each other fine, but if I go on speaker, the mic doesn't seem to work anymore. I granted every permission to Signal, tried rebooting, but no luck. Same issue happens with KakaoTalk.

I couldn't find any case of someone else reporting this, but I haven't done anything custom (that I know of?) on my phone.

If I record a video with Pixel Camera, it picks up my audio just fine. Duolingo doesn't seem to have an issue either.

Anyone know how I can debug this?

    dginovker

    You need to get a new device ASAP, 4a isn't secure at all anymore.

      dginovker The speaker used for non-speaker-mode calls is separate. It sounds like your other speaker is broken. The good news is that it's an end-of-life device without current GrapheneOS or ongoing security support which needs to be replaced, so it's not a big deal that the hardware broke. See https://grapheneos.org/faq#supported-devices and the other sections. Pixel 4a hasn't been supported for a while beyond legacy extended support releases. It's on a legacy branch of Android 13 QPR3 GrapheneOS while GrapheneOS is based on Android 15 QPR1 and very soon (days) Android 15 QPR2.

        I had that exact same problem too with my 4a and like you, I tried everything but I think this was just a hardware issue.