iPad WP app reverting "Visual" to HTML, unable to change this

Okay – so I hope that was a good enough explanation, but I’ll expand below.

I have edited my posts in the WP app on my iPad.

For ONE of my posts (I’m just starting out), I can edit it just fine, visually, through the app.

The next, I”m unable to do any editing in plain text, it’s all showing up in HTML and no matter what I do, there’s no way to change this.

I’m frustrated at how limiting the iOS app is. I really would like to have seen more to it, but… Anyway, this is an issue that’s making it very, very difficult to work with my posts. What can be done to fix it?