Just reread a few posts and r latest POA [to refresh my memory].
IMO it may be an idea to tweak your POA by adding in specific comment about the brand and ASIN’s Amazon have highlighted .
Keep the rest of the plan but add to the root cause and state that as a result of your lack of knowledge surrounding authenticity issues and lack of understanding of Amazon policy you listed items from XXX brand without having proper invoices or Brand authorization. State, however, that you do have retail receipts for the items in question and attach them with your plan [then remember to actually attach them]
Then in your next section specifically mention the ASIN’s and brand and state that you have deleted those items from your Inventory and ceased selling that brand.
You may get advice from others, so please wait before sending in a revised POA