Problem with PayPal business classification

A customer who has purchased from my website previously using PayPal was unable to complete payment yesterday for any order with PayPal.  He was told that his credit card, Citi, blocked the payment because PayPal is classifying my business as a commodities site for gold bullion, etc., but actually my site is selling antiques.  He tried repeatedly and the sale would not go through even though he completed a large sale only a few weeks ago.  While he only wanted to use PayPal, I tried to get him to use Stripe, and when he did that with the same credit card, it worked perfectly.  Is there a setting to classify my business with PayPal?  This problem has never occurred previously.  How can I change the PayPal classification for my website?