Huntgroup voicemail retrieval across SCN

[drobbo]

Site A:
IPO 500v1 running v9.0.0.829
VMPro 9 (non-centralized)
SCN Connected: Yes
Hunt group H1 (vm code empty)
User A
User B
SC *98
Feature: Voicemail Collect
Number: "?H1"
Line group: 0
SC *97
Feature: Voicemail Collect
Number: "?H2"
Line group: 92
SC *96
Feature: Voicemail Collect
Number: "?H3"
Line group: 92


Site B:
IPO 500v1 running v9.0.0.829
VMPro 9 (non-centralized)
SCN Connected: Yes
Hunt group H2 (vm code empty)
Hunt group H3 (vm code empty)
User C
SC *98
Feature: Voicemail Collect
Number: "?H2"
Line group: 0
SC *97
Feature: Voicemail Collect
Number: "?H3"
Line group: 0
SC *96
Feature: Voicemail Collect
Number: "?H1"
Line group: 32

Handset 5610
User A on Site A can dial *98 and get the hunt group H1 voicemail box.
User A on Site A can dial *97 and not get the hunt group H2 voicemail box.
User A on Site A can dial *96 and not get the hunt group H3 voicemail box.

Handset 9608
User B on Site A can dial *98 and not get the hunt group H1 voicemail box.
User B on Site A can dial *97 and not get the hunt group H2 voicemail box.
User B on Site A can dial *96 and not get the hunt group H3 voicemail box.

Handset 5410 (also tested from 9608)
User C on Site B can dial *98 and get the hunt group H2 voicemail box.
User C on Site B can dial *97 and get the hunt group H3 voicemail box.
User C on Site B can dial *96 and not get the hunt group H1 voicemail box.

Voicemail codes have been entered from Manager with no change in observed outcome. SCN is up and active between the systems and all other calling features and routing is working as expected.

There appear to be two separate issues observed:
* One user cannot access local or remote hunt group mailboxes
* Two other users can access local but not remote hunt group mailboxes

Searches produce similar experiences for v3/v4/v5 systems but nothing for later systems; centralized vm pro. What I'm looking for is advice on what to try/look at next while I wait for a 9608 handset to arrive for further troubleshooting.