Pandora Update - 9/10/2019: Hi, we're aware of an issue affecting Android listeners connecting to their vehicle via bluetooth where the song information appears to be blank.
We've passed this information along and will be providing updates as we receive them.
I had the same problem while using Uconnect system on my 2015 Jeep. Also, I was using a BlackBerry Keyone device. However, I was using Google play at the same time and the music would display on Uconnect. I just recently replaced my BlackBerry Keyone with a Samsung S9+ and Pandora music is displaying just fine on Uconnect as well as Google Play.
So perhaps this information will help other Pandora users who have Uconnect as well as Pandora reviewers to pass up this up to technical support.
I prefer Pandora as my preferred music service since I like the music suggestions it provides unlike other music services I have used.