Your hack has modified the savedata structure; PKHeX scans to make sure things are "proper", and your save is not.
The first savedata object is expected to have a size of 0xF628, but it seems yours is 0xFBE0 (larger). The box storage object is also too large, coming in at 0x1E4FC (not 0x12310).
So, your save struct is different from what PKHeX expects for a valid HG/SS save file, and is thus not an HG/SS save file.