dump cura and try prusaslicer instead.

Not sure why you would want unuseable 'margins'.
usually the defined build volume is also the printable area.

Also check that you haven't got any pre-extrusion lines or outlines that are outside the build volume due to the size of the model.

I've been caught out by that in the past.
I usually have my filament prep outlines 3mm from the model.
Causes problems on the rare occasions i try to use the fulll build plate width.