4.2.5 - volume drops mid mix

Hey!

I updated to latest Rekordbox 4.2.5 today and I'm now noticing that the output volumes drops mid mix, i.e. when I move the cross fader to the middle position on my DDJ-RX. I experienced this with a previous version but 4.2.4 appeared to resolve it. 

Has this issue reappeared? Or am I missing something obvious?

Cheers,

Tom