In LENS, you have the ability to embed an external website to an Update (for more information on how to do this, please reference this article).

Once you embed the link to the Update, LENS removes the "last updated" indicator on the Update due to our inability to control an external website, and when that website is updated. LENS is working as designed.

This is an Update without an embedded link, created just now:

This is an Update with an embedded link, created just now:

Please let us know if you have any questions!