Entry Meta Issue with Publish Date and Last Updated Date

Hi Guys,

I used this snippet below to show the updated date for my posts and hid the publish date and it works as expected on my old posts.

.posted-on .updated {
    display: inline;
}

.posted-on .published {
    display: none;
}

.posted-on .updated:before {
    content: "Last Updated ";
}

However, I just published a new article on my website and no date appears on the entry meta, only the author. I expected that the publish date would show as the last updated date or at least the publish date should show as Published On... since it's new and then Last Updated replaces it whenever it is updated. Shouldn't this be the behavior?

How can I fix this, please?

Thanks.