Anyone here using Teams with Business voice?

Have come across an "issue/bug/feature" - can see users in the contacts/speed dial pages, yet when trying to call those users, it only gives the option for "Voice", and nothing else to be able to call their mobile/office which is in the AD/Azure/Outlook profiles.

How do you transfer a call to another user's mobile ??

Using Teams voice is no good if the user you're trying to reach doesn't have internet where they are. :-/