Hi Jon,
I am not sure why the voicemail greeting would be different for internal vs external calling. I would recommend opening a case with Genesys Product Support if you are still having this issue.
With regards to accessing another users voicemail, this is not currently possible, but there is an Idea on the Genesys Cloud Ideas Portal: Voicemail Access by Supervisor which would be good to vote for and add your use case
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Sam Jillard
Online Community Manager/Moderator
Genesys - Employees
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