Let’s try a plain reply. Does this work?

And now with some class!

Here’s another Webmention comment.

And now another bare link: https://pljcbsntest1.mystagingwebsite.com/2019/12/webmention-test/

And now a bare link: https://pljcbsntest1.mystagingwebsite.com/2019/12/webmention-test/