As shown by the red box in the image below, the cutter stopper is in a non-printable area.
Follow the steps below to print at the full size of 256×256 mm.
1. Use a 2.0 mm Allen wrench to loosen the screw securing the cutter stopper, then remove the stopper.
2. In the slicing software, set the parameter of "Excluded bed area" to "0×0“.
The automatic unloading function will be disabled once the cutter stopper is removed. The filament should be unloaded manually.
1. Press the lever of the filament cutter backward to cut the filament.
2. Touch "Function - Extruder - Unload" on the touchscreen.
3. Remove the filament when the touchscreen shows "Unload completed".