SOLVED Voicemails not showing up until days after they were left

Same issue here. I just discovered a VM by dialing my number and hearing I had a 6 day old message waiting.  No notifications on the phone, I just luckily (out of the blue) decided to check.   Odd too is when I opened visual voicemail to see if it had the message, the app acted like it was newly installed  (started up with a splash screen advertising a "better" subscription version and then synchronized my messages).   I had used visual voicemail in the past so not sure why it started as if it was just installed.   

I too have been having this problem on and off for at least a year.  Unfortunately I don't think TMobile support reads these messages so don't expect much from complaining here.  Enough people need to call tech support over and over again before they might do something.