DJM-450 - Master and CUE out of sync / Master signal delayed

Hello everybody,

I'm experiencing a weird problem with my DJM-450. Master and CUE are somewhat out of sync. The master signal is delayed for maybe half a second (or even less) compared to the signal on the headphones which makes mixing impossible.

At first I thought something may be wrong with my sound system so I tried another amp. Same problem. I also tried other headphones. Same problem. I even tried different sources (line and phono).

Tried firmware 1.02 and 1.03. Same problem on both. A factory reset or adjusting some of the settings didn't help either.

This problem started just today. A week or two ago when I used the mixer everything was fine. The mixer is just for home use so it isn't used that often (once or twice per week for 1-2 hours max).

I'm using the RCA master out.

What could be wrong? I bought the mixer about 6 months ago. Is it already broken? That would be very disappointing!