Stranded Inventory - Seller Support Say it doesn't exist

Today I have a "fix stranded inventory" on the page. When I click on it is says "Restricted ASIN". There is 1 left in stock and I have no idea what is it, the asin or SKU are not coming up.

The SKU is GY-KY2W-6HUV and the ASIN is B001T3YDPK

I messaged Seller Support and they were no help whatsoever. I received this message.

Hello from amazon Selling Partner Support,

We understand that your query is regarding reinstatement of ASIN: B001T3YDPK.

In this regards, please be informed that we determine that their are no listing with ASIN: B001T3YDPK. So, hence we request you to kindly add listing in your inventory.

After that if you facing issue kindly contact us back again.

To help us continually improve, we ask that you take a moment to complete our survey below to tell us about your experience with this specific interaction.

Were you satisfied with the support provided?

Like how is this of any help! I cannot list it, I cannot even find what it is.