Headphone Mixing Dial - Weak Master Signal

Lurker here. I recently picked up a used DJM 800 which i've been using with XDJ 700's.

I have noticed that with the majority of my tracks I receive a very weak master signal through my headphones, and to receive a "50/50" of cue and master volume I end up having the dial set to around 3 or even 4 o'clock. I regularly use other gear like DDJ400 and XDJ RX where the 12 o'clock position achieves "50/50" with the exact same tracks.

Is there an issue with the mixer? Or, ideally, is there something else i'm missing to correct for this?

Appreciate any input or advice.