How have you set your wall thickness because the amount you specific in cura is divided by your nozzle diameter. So we always use a wall thickness of 0.8mm when we have a 0.4mm nozzle so thats two extrusions for each wall (if you see what I mean, sorry if the is confusing)
So its always best to set your wall thickness to be a multiple of your nozzle diameter. So setting the thickness at 2mm might be causing your issues. If you have a 0.4mm nozzle then try a setting of 1.6mm which is 4 extrusions for each wall.
Cheers,
3DEX Filament