I'm not sure what's triggered it - I THINK it has something to do with a force-resync, but not sure.

I'm no longer viewing my full list of shared mailboxes. I used to have a number of users shown - they had all had their ACL's set individually and were shown in the list. "doveadm acl debug" shows they SHOULD be shown - at least I think so, as the output for the mailboxes that DO appear is identical for those that don't.

Where should I look for breakage?

Daniel