Xiaomi
Restrict Floating Notifications in Do Not Disturb auf Xiaomi
Do Not Disturb on MIUI is meant to keep your screen calm, but by default some apps can still push a floating banner across the top of the display. This happens because the floating notification layer runs independently from the silencing of sounds and vibration. Messages still arrive and stay in your notification shade, only the visual pop-up is the issue.
You can turn this behavior off directly from the sound settings. Go to Open the Settings ➔ Tap on Sound & vibration ➔ Tap on Silent/DND ➔ Enable or disable Restrict floating notifications.
Enabling this option suppresses the pop-up banner for every app while DND is active. Disabling it lets banners appear again, even though sound and vibration stay muted. Nothing you do here deletes or delays a message, it only changes whether it interrupts your screen visually.
If you only want to silence specific apps instead of everything, app-level notification settings are the better fix. Use this DND option when you want one single switch that applies across all apps during focus time.