im experiencing the same exact problem as VjSlim, im using the ddj rev5 and running sonoma 14.4.1
i did find a work around the problem so it would export by not recording any audio to MIXEMERGENCY by doing that it would export just the video mix and i would use the audio from the recording of serato. i hope you guys fix this issue asap. before the ddj rev 5 i had the ddj sr2 and everything worked perfect. this issue only happened with the ddj rev 5, because it also happened with sonoma 14.4 and with the ddj sr2 it didnt.