Ahh, that's the issue; Nostr connect doesn't support NIP-44 encryption yet (what is used for the DMs on Shopstr, Amethyst, Coracle, 0xchat, etc.), so you can't view the messages unless you use another extension like Alby or nos2x. If you have 0xchat, Amethyst, or Coracle you should also be able to view the messages there an claim your payment.