I think I have the same repeatable Bluetooth phone-call microphone issue with my Garmin GMA 350xc audio panel in my helicopter. Issue summary: When my iPhone is paired to the GMA 350xc, I can make or receive a phone call and I can hear the other person clearly in the headset, but they cannot hear me. In other words, the Bluetooth connection passes incoming call audio to the headset, but my headset microphone is not being transmitted through the GMA 350xc Bluetooth path. System details: Garmin audio panel: GMA 350xc Headset: Bose A320 New phone: iPhone running iOS 26.5 Older comparison phone: iPhone running iOS 14.2 What I have already tested: I turned off all other Bluetooth connections and paired only the iPhone to the GMA 350xc. In that configuration, the call connects and I can hear the other party, but they cannot hear me. If I disconnect the phone from the GMA and instead use the Bose headset’s own Bluetooth connection, the microphone works fine and the other party can hear me. Bluetooth Recording Mode on the GMA was checked and is definitely OFF. I tested with an older iPhone running iOS 14.2, and the GMA 350xc works consistently with that phone, including microphone audio on calls. My newer iPhone has had this problem consistently on iOS 26.x. I have tested since iOS 26.2 and now on iOS 26.6, and the problem remains the same. The issue appears to have first come up when I moved from an older iOS version to iOS 26, although I do not have the exact version transition documented yet. Current conclusion from my testing: The Bose headset microphone appears to be fine. The problem appears specific to the GMA 350xc Bluetooth call-microphone path with newer iPhone iOS 26.x versions. The GMA Bluetooth connection reliably provides incoming audio, but not outgoing microphone audio, with the newer iPhone. The same aircraft/audio panel setup works properly with the older iPhone on iOS 14.2. Can you please advise: Whether this is a known compatibility issue with GMA 350xc and iOS 26.x Whether there is any Garmin firmware/configuration update or workaround Whether there are any additional diagnostics you want me to run