Are you brand registered as an authorized retailer or own the brand yourself?

Is the IP you got dinged with your brand or another brand you don't sell?

Since you are saying you are no longer able to edit your listings, it seems either your brand was removed from brand registry or you were removed from the brand's authorized retailer list.

If you were dinged with an IP you don't sell:

• Check your KWs. Back end. It isn't always visible but the list - I can go in, put in our brand name and find every single listing that uses that word.
• Check if you have any other logins - the notification could have been sent to a different login account (our brand registry hosts different brands, from ones we manufacture to ones we have the rights for).
• Send these screen shots showing there was no notification or details over to seller support and then keep pushing the same ticket for clarification or removal of the ding on the account.

If you were dinged with your own IP:

• Check brand registry and see if your trademark is still valid and your registration active with Amazon.
• Check if there is an issue with your trademark registration (was it pending?)
• Open a case with seller support on this. I had to do this recently as we got hit with an IP violation of our own brand. Once I confirmed our brand is still good with Amazon, I just sent that over the seller support because it was a Catalog issue. Somehow a physical product with the correct catalog location was being identified as a digital download and caused the issue.