iPad Camera App External Audio In Problem

HI,

Using my iPad to record using the camera app my friend and I playing music. I have the output of my PA mixer going into the iPad via the lightening port. Using the app Recorder Plus I can verify that the iPad has switched over to using the USB Mic and Speaker instead of the Builtin Mic and speaker. Recording works fine every time. When I switch to the camera app I have learner that you need to unplug USB cable, launch the camera app and then plug in the USB cable for the Apple camera app to make that switch. SO far so good. Record a video and it works. Stop it and using the little left arrow go back into record mode. Start another recording (at this point the little sound indicating recording has started can be heard through the PA so the app seems to still know I am using a USB connection for audio. Yet, when I go to replay the video the little speaker icon is greyed out and there is no audio on the video. I have repeated all of this several times and it seem the camera app just randomly stops using the USB input for audio in. This makes for a VERY unreliable video recorder with a USB audio input. Of course it fails to record when you have just played the PERFECT version of a song.... Any suggestions?