You have something else going on somewhere. I just tried your files on a test site. The test site is a WP install, latest version. It is using the 2017 theme. It has only ACF Pro and your plugin active. I created a textarea field named ‘funbotic_parents’. When I go to a page where this field appears it is set to readonly.
There is something in either the theme or another plugin that is interfering with your plugin on your site.
