Pioneer DDJ-SX2 - Inconsistent Gain on channels (hardware issue it seems)

Hi!

I've just recently upgraded to an SX2 from the SX and have noticed inconsistencies with the gains on channels. This appears to be hardware based. I turn all my EQ's and trim to the exact same point on Channel 1 and 4 and play the exact same track, at the exact same time and my audio levels appear different (channel one's gain will hit roughly 1 coloured LED above channel 3's consistently).

Video here: https://drive.google.com/file/d/1YfdV_xDD1MMgU8OHXd_JW9HF4JybPplt/view?usp=sharing

Can someone please help or shed some light on this?

Kind regards,

Michael