DJM Rec: Live Stream, mixer output, App picked up cue tracks.

I recently played a live FB streamed set. Unbeknownst, during that performance, the cue'd channel was being picked up by the app and broadcast. Ergo, the audience could hear what was being cue'd and the playing track was silent. However, the output in the studio monitor was fine and as expected.

Is this a known issue or is there a setting I have either turned on or turned off?

iOS - 13.3.1

CDJ 2000 NXS2 - 1.85

DJM 750 Mk2 - 1.04

DJM Rec  -1.2.3

I also used an original Apple cable.

Thanks in advance.