Has anyone had problems with the in-call volume level with the HTC One? My phone worked great for a few months, but then the volume in calls got very quiet, it is almost impossible to hear anything. It doesn't seem to matter whether the calls are outgoing or incoming. Voice quality is also quite low, many callers are garbled.
I've resorted to using speakerphone, since that is quieter too, I can hold it up to my ear. But this is not ideal in all situations.
I've tried all the settings combinations including Beats Audio and Bluetooth on/off with no success.