It could just be me being silly but even in the demo video of measuring dc voltage it shows 10.37 dcv and its a nine volt battery i just tested a 3v battery and its saying 34.57 dcv probe and scope set to x1 please assist
Aparantly, you have set your unit to ‘x10’ in the menu, that’s the reason for it to display the values multiplied by 10.
Next, before performing a DC measurement, always switch the input coupling to ‘ground’ for a couple of seconds, this allows the unit to restore its DC reference and makes sure measurements are correct. All this info can be found in the manual.