Sunlit and iOS app working with Wordpress?

Sunlit and Micro.blog iOS app used to work with my Wordpress site, but I just tried posting today and I got this error on Sunlit:

<p>There has been a critical error on this website.</p><p><a href="https://wordpress.org/support/article/faq-troubleshooting/">Learn more about troubleshooting WordPress.</a></p> (error: 500)

The error included all the HTML tags.

I thought it was because my images were too big, but even after resizing I was still getting the same error message.

Then I tried posting just a text message using the Micro.Blog iOS app and I get the following error:

An error occured. Please try again.

Just to double check, I went to micropub.rocks to check my website and everything posted just fine through that. So I’m not sure what I’ve done wrong.

Is this related to the Debugging micropub setup issue?