you can try (if you haven't) to change the configured bluetooth mode. This fixed many headset+controller related issues for me.
There's usually a file:<li><code>/etc/bluetooth.conf</code></li><li><code>/etc/bluetooth/main.conf</code></li>
Which has the property:<code># Possible values: "dual", "bredr", "le"<br>ControllerMode = bredr # Default is "dual"<br></code>