The chime is unlike any other sounds on my IiPad. It doesn’t seem to be associated with other devices, but I’ll continue to look for a connection.Does it happen when other devices are receiving messages? I get alerts on my iPad and Apple Watch when I receive text messages and phone calls.
I thought I turned off sounds on all of the listed apps, but I’ll check again.Go through Settings > Notifications. Look for apps that have Sound turned on. You can see this in the main list along with the app name. Turn off sounds and any other notifications you don’t want.
Not all apps offer all notification types.