Settings are now identical between both phones. Unfortunately, i’m still not able to streamto chromecast devices with the new phone.
I will play around with the settings. In case I still do not achieve an improvement I will post my settings here.
EDIT: For your information
new phone: Motorola Moto Z2 Force (Android 8.0.0)
old phone: Motorola Moto Z (Android 8.0.0)