BTT Mini E3 V3 - CR10 not printing to slicer scale

[Snooth]

Hello,

Looking for some help here, I've got a CR10 V3, I've confirmed the Marlin firmware to be an almost stock printer with no other settings (BLtouch etc.., it's a basic as it can be).

The issue I'm having is that the print bed is 310 x 320, I've changed this also in the Marlin firmware before building it. The printer doesn't print the whole size of the bed, in fact it seems the prints and print bed is 40% smaller, even the prints are printing 40% smaller than what is sliced.

Has anyone seen this before?

Snooth.