Keeping a constant Bluetooth stream to older Alpine receiver

Hi everyone,

It's my first post here and I have a bit of a technical issue with Bluetooth on my new Alpine UTE-42BT when streaming sound to it from my Pixel 2 Android phone. It's installed in my class B camper van (and home) and wired into the house batteries so that I can use the car's audio system as a sound system whenever I want. I'll try and make this brief.

How I expect a BT receiver to work:
You pair and connect, then all sound from your device goes to the receiver and into the speakers. This is how it works with my BT headphones.

How it's currently working with my Alpine + Pixel:
I pair and connect.
I can start playing a song or a video, and the sound is streamed to the receiver and played on the speakers. The receiver knows when it's "playing" something and shows "pause" if I pause the song/video from the phone or from the receiver itself.
Once paused, certain apps, like the Android system sounds, Instagram, even some audio players playing a local mp3 file, are silent. They play on the phone but because the receiver is still in "pause" mode, no sound is playing through the speakers.

It appears as if only some apps send the proper "play" signal that audio should be played. I have found a way to trick into playing all sound: start playing from an app that works, pause it. Clear the app away, and then press play on the receiver, which will continue to show PAUSE (since it couldn't actually resume playing because you cleared that app). All sounds from the phone will then play into the speakers...until the next time you play and pause from an app that works to begin with. This is not a problem when pairing my MacBook. It just plays all sound coming from the computer.

Has anyone come across this? Is there a way to keep an open stream of audio going between the phone and receiver?