did you ever figure this problem out?
i know it's months later but i'm having a similiar problem with my lumia 635.
i'll have full bars and my phone never rings or shows i have a missed call. i'll get no notification about a voice mail message until hours (sometimes days) later!
sometimes i'll get a call and then when the call is through i get a notification i have a voice mail...once from 3 days prior!
my husband has the same phone and is having the same problem. he'll get a call, then when he hangs up he'll immediately get a voice mail notification and it was a message that came in a day ago.
why does our phones have to get a another call before it will notify us of a voice mail message?
in all cases it never shows you you had a missed call or a voice mail.
this has happened several times when my husband has called me....i have 4 bars service and my phone never rings. he gets sent right to my voicemail and i don't get the message for hours.
it's making us both want to go get a different phone to see if it's just the phone or the network.
was just wondering if you ever got it solved,
thanks!