Please email supportdos@larian.com, with a brief description and a save with that backpack; that should make it easier to identify the display problem (I'm assuming you don't actually have that much weight in the bag, with nested containers, or something... though that would be worth a bug report also).

For the PC version, the report.zip file generated by the D:OS support tool will include all your saves, in addition to system and game information. To reduce file size, you can delete all but one save from the zip.