If anyone else is having issues with this, we need to slam apple with reports of this one, by slamming I mean let them know and flood them not be rude.
To me this is a serious one.
Can anyone confirm this one?
iPhone SE, IOS12.1, voicemail tab of the phone app, the voicemail already needs to be already listened to, doubletap on the voicemail and try to replay it again using the play button. I had one voicemail that when I double tapped on play I some how landed in my phone favorites, I tried to play another one and when I double tapped on play it did nothing. I restarted my phone and same behavior.
My only work around for this is texting the voicemail to yourself by double tapping share and then double tap message and just type in your own number.