Smartphone Call Display Fix (Xiaomi HyperOS)

I'm experiencing an issue with my smartphone where incoming WhatsApp calls aren’t showing on the screen while other applications are running. I can hear the phone ringing but nothing appears on screen. Note that incoming WhatsApp calls work fine when screen is off, i.e. when I'm not actively using the phone. The phone is Xiaomi 13 Ultra running on Hyper OS (variation of Android). All notifications for Whatsapp are turned on. I did give all available permissions to WhatsApp, but it seems that the phone won't give me the option of "Display over other apps" to be controlled for WhatsApp (it is just not on the list). I did some online research and tried to manually adjust this permission using adb commands, using "appops" and "pm grant" commands, but that also didn't allow giving the permission to WhatsApp. I'm looking for someone with a robust skill set in mobile troubleshooting and app conflict resolution to address this problem efficiently. I'm open to any smart fixes that can get the problem solved without causing harm elsewhere. Key Requirements: - Experience in mobile software diagnosis - Proficient in Android systems - Understanding of app notification hierarchy - Capability to suggest and implement solutions - Clear communication for potential troubleshooting steps Ideal candidates will have a proven track record of resolving similar issues and are encouraged to share any relevant experiences in their proposal. Your expertise will help ensure the seamless functionality of communication apps on my device.