Share your experience!
Hi @Collo98,
Sorry to hear this, I understand that it most be frustrating for you. 
How often would you say this happens, more than once every day?
Have you tried restarting your phone into safe mode to see if this still happens? Safe mode temporarily disables downloaded applications so if this happens to be caused by one you should not experience it in safe mode. I understand that it might be hard to test depending on how often this happens but it would be a way to rule out that an app is the cause.
Please let me know what you find. 
hi got problem with my z5 premium it's when im getting phone call there is no audio no sound! all other audio and sounds work like text and email notification but when im getting phone call no ring tone!! just shows on screen what to do now!?
please jelp
cheers
@Collo98 Sorry to hear that uninstalling some of your apps didn't solve this. I'm afraid that there is no easy way to troubleshoot something like this. Another way would be to uninstall all of your download apps, then install those that are essential for you and continue from there until you encounter the one(s) that causes this behaviour. I understand that this can be inconvenient though. 
Hi @madmatt32, I'm sorry to hear this.
Do you get no ringtone as well as no sound during the call itself, as in you can't hear the person calling you? Have you been able to test safe mode as well?