Digium D40s and DPMA; Directory does not always update

I have a client using FreePBX 12 w/Digium D40s on DPMA (firmware v1.4.2.1).

If I change the name on an extension/phone, the Directory on the D40s will update accordingly.

But, I had to swap existing names between (2) extensions. This change does not update the Directory, even if I reset a phone, it still comes up with the old entries for these (2) extensions after reprovisioning.

Any ideas on how to fix this, other than deleting both extensions and starting over?