Plugin Causes Post Featured Image to be Intermittently Lost

I’ve been using EditorsKit, because I do a lot of subscripting and superscripting in my Gutenberg <p> and

blocks. Unfortunately, I was having a problem with the featured images being dropped from my posts while editing. Notably, this often seemed to happen when Gutenberg did an autosave. During troubleshooting, I disabled this plugin and the problem seems to have gone away. I have been editing a particular post all day, and haven’t seen the issue reoccur. Of course that doesn’t mean it won’t happen the next time I’m editing after I finish posting this comment. In the meantime, though, the plugin will stay disabled unless I’m really doing a lot of <sup> and <sub> work.

Thought y’all would want to know.

The page I need help with: [log in to see the link]