Symptom
Poly phone shows busy but 8x8 Work for Desktop and 8x8 Work for Mobile are working as expected.
Applies To
Poly Phones
8x8 Work
Resolution
Make sure that the extension Contact Directory Scope is set to PBX.
Log in to 8x8 Work
Click Users.
To the right of the user you need to edit, click Edit (pencil icon).
Under Basic Information, select PBX as the Contact Directory Scope.
Cause
This is normally caused when the directory scope is set to Company.