The issue seems to be intermittent and will sometimes not appear during a session. It seems to occur during an editing session. When I try to undo an edit the undo line reads: Undo Set 'Volume' to '0.4', and when I try that, nothing happens. Then when I look in the mixer, some tracks are set to + 0.4. If I try to reset them to 0, they will automatically re-set to +0.4.
Once my session has gone into this mode, I've noticed that the problem happens whenever I highlight a track to work on it. Sometimes I will add a blank track (just to make it easier to highlight the track above) and I've noticed that the added tracks will sometimes also be set to + 0.4. However, some sessions have gone smoothly without the issue happening at all. Any help would be appreciated.
Please note that I'm fairly non-technical. Also, I'm using an UA Apollo Twin through a Mac Mini 2012 / 2.6.