I have a pretty new set of NC 700 Headphones which I have typically have connected to both my iPhone 11 (iOS 13.5.1) and my MacBook Pro (13-inch, 2019, macOS 10.15.5). The Bose Music mobile app version is 3.4.1 and firmware is 1.4.12-6283+9f658fd.
The problem manifests when my headphones are connected to my iPhone and I start typing. While I type, the volume starts to go up steadily. It also doesn't seem to matter which iPhone app I'm using. It happens when I am typing in Safari, iMessage, and other apps.
I recently reset the headphones to original settings to fix a connection issue with the Bose Music app, which occurred shortly after I first received them. I am not sure if the issue was present before I did the reset. Other than that, I have not performed any other troubleshooting.
I'm sorry to hear of this issue, I would recommend clearing the pairing list on your headphones. I have included the LINK HERE to assist you with this. Once complete, delete the pairing on your phone and try again.
Let me know how you get on!
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