Hello Cloudy_day,
Thank you for reaching out to Apple Support Communities, and we'll be happy to help in any way we can. We understand you're having issues with your Do Not Disturb banner getting stuck. Have you tried restarting your Mac? This simple step resolves a multitude of issues: Shut down or restart your Mac - Apple Support
"On your Mac, choose Apple menu
> Restart.
If you don’t want app windows that are open to reopen when your Mac restarts, deselect “Reopen windows when logging back in.”"
If that doesn't resolve the issue, does your Mac need updating? Do you have a recent backup for the data in your Mac? If not, we recommend that you create one as described here: How to back up your Mac - Official Apple Support
Then update your macOS as outlined here: Update macOS on Mac - Apple Support
We hope this helps.
Cheers!