Music constantly stops on Android and connection to chromecast is lost

[user-removed]

Plan

Premium

Country

Belgium

Device

Samsung Galaxy S9 Kernel 4.9.59-15776989

Operating System

Android 

My Question or Issue

When my music is playing while my phone is connected to my Bluetooth headset, it constantly stopt the music and I have to restart it. It's the worst when I'm biking. The last ride of 10 minutes, I had to restart the music 67 times. I went crazy...

This also sometimes happens when my phone just lies at my desk with nothing touching it.

When my phone is connected to the Chromecast at home, it also loses connection now and then and then I can't switch, or pause tracks anymore. Then ai have to force kill the Spotify app, restart my chromecast and then it works again until it doesn't anymore... 

I've been using other music apps like Google Music for years now and wanted to see if I would switch but with this issue, I don't know if I'll do. I never had such strange issues with the other one.