Please tell us some basic information before asking for help:
Model Name: ZenFone6
Firmware Version: 18.0610.2101.132
Rooted or not: not
Frequency of Occurrence: since update to Android 11 (even after factory reset done)
APP Name & APP Version (If your issue relates to the app):
In addition to information above, please also provide as much details as you can, e.g., using scenario, what troubleshooting you've already done, screenshot, etc.
When 'Do Not Disturb' modus applied and 'Contacts with star' modus is on (allowing to interrupt) the ring volume is not working when such a contact tries to call me (I only see the screen's showing the caller). Please advise.