Audio player settings for my phone

I don't know what is going on, but my phones music library doesn't seem to work well with the Bluetooth on my stock headunit. I have to browse and play my library on the phone. Shouldn't I be able to browse and change songs on the headunit? I have a new Samsung S7 Edge and put the contents of my ipod classic on it, about 3000 songs. My phone connects to Bluetooth just fine, but when I try to play songs all it does is show the last song played and I can't even start playing that. Only when I fire up my google play music app does it start working. Do I have a setting wrong? Maybe I need to use a different audio player app? Any advice is appreciated.