It turns out that commenting has been affected by something strange. When logged out on this site on my phone and try to leave a comment, I get the error
Nonce verification failed.
In the meantime, I have made available a contact form for anyone who wants to get in touch with me (there’s another story there) until I’ve fixed the comments.
I will continue to work on fixing the comments, and will let you know when they’re fixed.
I’m sorry for any inconvenience this has caused.