Using DJM-900 NXS2 v2.07 and the latest DJM-REC app. I had some issues with recording between A and B, A was recording but B wasn't. From the forums it seemed that there's an issue with setting the FX and the app will only record on channels that the FX is covering.
If I switch to "Master" FX, then I hear both and can record both A and B decks, but the FX are not part of the recorded mix. Also - when mixing I like to apply FX to just one group (e.g. to A but have nothing on the B).
Is there a way I can use the app and my mixer to record like this or do I need to look into an alternative - I want to capture exactly what is being output on the master mix.