Problems with connection phone and chromecast (only with spotify)

[Elleo9]

Plan

Premium

Country

The Netherlands

Device

Xiaomi Mi 9 SE

Operating System

Android (latest version) 

My Question or Issue

Since a few days I have problems with playing music. I can make a connection and play music via chromecast. But when my phone screen is locked and I want to skip a song or change the volume, the connection is gone and music continues on my phone in stead of the chromecast. Then I have to reconnect to find myself in the situation over again. Problem happens too when I have my screen unlocked.

Tried several things:

- Check if my wifi adresses are the same

- reinstall  Spotify

- Reset Chromecast

- Restarted my phone

- Restarted router 

It's very annoying and I hope there's a fix for it.