The forums are filled with similar stories. Most likely, your photos have been stolen and appear on other massive wholesale sites.
Have you done reverse-images searches? You will then need to file DMCA takedown notices for each site/listing. Provide proof to etsy that you are actively defending your IP (photos). That may speed up the process.
Judging from the posts here and what percentage of sellers use the forum, this is happening to probably hundreds of sellers.
Diversifying is a good idea BUT if you sell the same things on your own or any other site they seem to be removed for that reason as well.
So if you do try selling elsewhere, be sure to use different photos.
"Despite providing extensive documentation proving I had the rights to sell these products"
What were you selling?
Do you actually make these products? Or did you design them? Are they vintage?
I see identical items being sold on Amazon and Ebay using identical photos. Your banner photos are on Aliexpress.
I don't see any photos of your workshop in your About section, or proof you make these yourself.
I can see why Etsy is confused.
Sounds like you might be an authorized reseller for the products? If that's the case they aren't allowed on etsy. If these are your original designs, and you are having them manufactured, you are required to list your production partner(s).
@2di4jewelryoriginals
It's much more likely that the seller is 3D printing another artist's designs, with a commercial license from the designer.
That would make the items Etsy-legal, but it could be that other sellers are using the same design file, so Etsy sees that as the same item.
@BrooklynBridgeStudio: "I had the rights to sell these products ..." As pointed out if you are using someone else's design file (or mold, etc) to make them there is a good chance that Etsy will see them as the same item available on a wholesale site or in other Etsy shops. Even if it is your own design, similar seems to be getting flagged.