[Plugin: Post Type Switcher] Can't convert a page

I have a page, that I downloaded this plugin for so that I can convert the page to a post. In the Page Edit view, I use the plugin to select ‘Post’, then OK. When I click Update (to save the page/post), it goes back to being a page.
I created a new ‘test’ page to verify this, and it is broken even for a new blank page. Sorry to be the bearer of bad news! ??