I tried to reproduce the described problem in a sample page that was prepared according to the provided information, but to no avail. You can find it attached to this post, please compare it to your actual project and check if there are differences in the setup.
You can check whether there are server-side settings or CSS styles that are overriding the specified title and icon of the notification.
If you are still having difficulties, please send step-by-step instructions for modifying the attached page so that the problem can be reproduced in it. This will allow me to inspect the issue locally and suggest a concrete solution.
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