Add featured image when saving the post

I enabled “Add featured image when saving a post” in setting and also “Find or generate”.

When I save the post as a draft after writing a few lines without inserting any image, it will automatically generate the featured image from the title.
However, when I add some more texts and images to the post and save again, the featured image does not update anymore.

Any advice on setting so it will pick up and update the featured image from “image in the post” when I insert it afterwards?

Thank you very much.