Archive mailbox does not appear in OWA, does appear in Outlook

I've got a really weird problem here. I've seen an archive mailbox not show up in Outlook, and typically the solution is to recreate the mail profile. But this is the first time I'm seeing the archive mailbox appear in Outlook and not in OWA.

We're testing archive mailboxes now, we're considering deploying them. One of my testers tells me that he doesn't see his archive mailbox. I log into OWA and I don't see it either. I confirmed that he does have an archive mailbox enabled in EMC. Powershell shows that he does have an archive mailbox (get-mailbox User -archive). So I create an Outlook profile for him on my computer and I don't see it in Outlook either. Then I do Test Autoconfiguration to see the Autodiscover XML, and his archive mailbox IS in the autodiscover. After doing that his archive mailbox becomes visible for me in Outlook, but it's still not appearing in OWA.

I've tried moving his mailbox to a different database and disabling and renabling the archive mailbox, even on different databases. I'm out of ideas.