I set up a page to display Webmentions of this type but ... Webmentions are not being displayed. I don't think it would have mattered. Akismet would have automatically approved your Webmention and I would not have seen it anyway. The only reason I know you sent a Webmention is because I saw them on the dashboard of webmention.io. Sometimes when I send pingbacks they are not received at the other website and I can't receive pingbacks from that website. An example here: https://dutchgoesthephoto.net/2018/08/06/tuesday-photo-challenge-round-up-120/#comment-15232
I don't mean to sound like a broken record, but as you know, I am frustrated by "it doesn't always work" when using the IndieWeb plugins. It can be challenging to troubleshoot if the problem is the theme, another plugin, server issues, etc. In the past few months, I have chosen to ignore the problems because the technical issues use up free time that I could be doing something else.