Strange “lea” prefix on wp-json

I found it. There’s a bug in the TotalPress.org Custom Post Types plugin in the file:

wp-content/plugins/custom-post-types/custom-post-types.php

At the top of the file, you will see the mistake:

lea<?php

When I remove the lea, the problem goes away. I’m contacting the plugin developer to let them know. Plugin version was 3.0.12.