Cannot delete annotation

Seems like a bug in the plugin you are using. You can remove it from the layers panel or contact the developer of the plugin to report an issue.

I just discovered, the annotation of the layer that I set up invisible should not be visible, but I think the issue is that this annotation is visible and cannot be deleted.

I don’t know if it’s a bug, but if you set this layer to be visible in design mode, you can edit this comment in development mode.