Parallel Import - Being asked for an invoice from an EEA distributor, but being rejected when it's provided

At my wits end now, cause I'm being threatened with an account suspension over this.

A few days ago, three of my ASINs were hit with Parallel Import violations. The three ASINs were all aprons, all the same brand, but three different colors. Red, green and blue.

The warning said I could provide an invoice from an EEA based distributor to counter the accusation, which I did. It was accepted for the red, accepted for the green and the two of those were overturned easily enough. All three ASIN were on the same invoice, bought at the same time. And the invoice was obviously ok for those two.

But the same invoice is being rejected continually for the blue ASIN. It just says they don't have enough info, and to try again. I tried contacting seller support, who said it wasn't their team, so they couldn't give me any sort of further information. Just to try submitting the invoice again. And it's been rejected again.

I'm not sure what to do here. I can't provide any of the other documents, and the fact the invoice worked on the other two suggests it's perfectly fine as an invoice. But I can't get any further feedback as to why the requested invoice isn't good enough for Amazon on this specific ASIN :/

Don't suppose anyone would have any advice or guesses why it's being rejected (it has all the things on it requested; item, address of the distributor, address of mine, covers the right quantity of product listed, and is dated correctly).