Chrysalis, I must say you've lost me with your last 2 posts.
The firmware on zyxel site and my device is "V5.11(AAVF.3)C0"
This makes me think you're discussing the VMG3925-B10B, as the firmware you mention matches that device, however
Made a new admin account, same as admin except firmware upgrade visible but no TR options (or VOIP).
The VMG3925-B10B does not have any VOIP menus, it has no VOIP ports.
This thread was specifically for the VMG8924-B10A, but you're discussing VMG3925-B10B firmware numbers, but your looking for VOIP menus.
Can you confirm which device you're asking about?