I’m stuck. (updating Brand Name value from “Generic” for Brand Registry application)

I have been going back and forth with Seller Support for days now and am so frustrated. Coming onto Reddit to see if anyone has been through something similar.

Backstory: I sell prints of my own artwork, for which I have GTINs. I have a pending trademark and I’d like to apply for Brand Registry.

In order to apply for Brand Registry, I need the following (according to Amazon’s Brand Registry application):
“Enter 1 to 3 ASINs that represent your brand. The brand name on the application should match the brand name on the ASIN.”

On my 4 listings, the brand name is listed as “Generic.” I set it to “Generic” following Amazon’s Brand Name Policy. I have been told by Seller Support that I cannot update the Brand Name value to my brand name (it creates confusion apparently). Fine. So I need to create new ASINs which are identical to my existing 4 listings, which have the Brand Name value set to **my brand name** and not “Generic.”

I tried to create an identical listing but received error 8541 under the Brand Name value:

8541: The value **my brand name** specified cannot be used as it conflicts with the value ‘Generic’ for ASIN **my ASIN** in the Amazon catalogue. If this is ASIN **my ASIN**, update the value to match the ASIN data. If this is a different product, update identifying information (UPC/EAN/Part Number/etc.).

I tried deleting one of my ASINs to create a new ASIN with the same GTIN, but I received the same error 8541.

How do I proceed? (Losing my mind over here)