Daniel, yourdoesn’t have the proper webmention markup. This is what you have now.
In reply to Khürt’s <a href="post about the Now page">https://islandinthenet.com/in-the-now/</a>.
HTML for a full proper webmention would be:
In reply to Khürt’s <a href="https://islandinthenet.com/in-the-now/" class="u-in-reply-to">post about the Now page</a>.
If you are using Webmention.io to send Webmentions then correct markdown would be:
In reply to Khürt’s [post about the Now page](https://islandinthenet.com/in-the-now/).
Until it links correctly, my website won’t receive a proper Webmention.