I have an iPad that when watching video and listening to music via Bluetooth, the video audio is out of sync and music lags. Does anyone know what's going on and is there any fix to it. Uconnect website says I don't need a update.

 

This is because you're watching the video in "real time" and the listening to the audio in "processed time". The audio has to be sent in audio packets to Uconnect (and actually any other BT device), then it's interpreted from BT packets to an audio signal which is then sent thru wires to the stereo which then sends it out to the speakers.
The only way to fix it (and as of now there isn't one available) would be a BT profile that would tell the tablet when you're streaming the audio thru BT and then cause the video to be slightly out of time to the audio.