How to update identifier_exists through Shopify?

GTIN: If the barcode is 12 to 14 digits, it will not be cleared

MPN: If the barcode is cleared, the mpn will be cleared

So if you want to keep the MPN, and Brand, then don’t use those rules.

The video I shared, is applicable to most merchants, yours seems to be different, so only apply what you need. Or don’t apply anything at all.

As you seem to need to keep the MPN values.