Since the last updates DJays closes after the first one or two songs. This issue isn´t connected to the music file itself. After a shutdown, I re-opend DJay and it played the song without problem. Also, after the second opening of DJay, it does not occur that the app closes itself.
I use DJay for a few years in my current setup daily. No additional equipment is connected and the iPad is not in active use when playing music. Sound is going over headphone jack. I only use Automix which is playing a playlist from music.app.
iPad Pro 9,7" (2016)
iPadOS 16.7.11
DJay 5.4.2