I've never had this one before, and I don't know whether my recent upgrade to Ableton 11 is to blame, but Battery 4 encoders have started reacting erraticly to mouse gestures: it's as if I'm trying to move them off an automation curve and they're trying to get back into it. The problem seems to disappear when host automation is enabled and the encoder is controlled via Ableton's "Configure" option. Also, there's no problem when in Logic X or in standalone mode.
I've no other external controllers connected, and there's no automation, so MIDI interference should be out.
Anyone with a helpful suggestion?