Originally Posted by
username
One problem I found out setting up my Tello is that for Visual Voicemail to work, you have to be connected to the Tello network via cellular. This apparently is how Visual Voicemail was designed and is not unique to Tello. So, it is a downside if you rely on Visual Voicemail (which downloads and transcribes voicemail messages to your phone) and are overseas using a data eSIM (instead of having your native carrier's data roaming enable). In Tello's case, they don't even offer roaming so this is not possible at all.
With AT&T postpaid, I receive Visual Voicemail when using WiFi calling and cellular data disabled.