Spotify control not working on Pioneer car stereo

[Java_SE_Binary]

Device

Oneplus 6 / Pioneer

Operating System

Android 9 Pie

My Question or Issue

My Mmh-2300nex is supposed to be able to control Spotify, and it used to on my phone, but suddenly it stopped working, reporting that a device is not connected, yet Bluetooth audio works perfectly fine. 

[MongoNC]

Hi.  I had the same problem and found the solution in this post.  I'm now able to control Spotify through the radio instead of having to use the Bluetooth option.

https://community.spotify.com/t5/Android/Spotify-will-not-connect-to-Pioneer-MVH-2400NEX/m-p/4629376