Readability – Mark this result in the text

Hello!

The plugin seems to pick up and analyse my content (from acf whyiswyg) well. Under the readability tab, it gives back analysis of the (acf) content, like:

1.8% of the sentences contain a transition word or phrase, which is less than the recommended minimum of 30%.

When I click the button (eye), ‘Mark this result in the text’, it does not seem to work on the acf wysiwyg editor, in other word, it does not highlight the text. When moving the text to the main/standard wysiwyg editor, it does highlight the text!

I am running the latest version of WP and plugins, with only ACF Pro, Yoast SEO and your plugin activated. The used theme is Twenty Seventeen.

Could you have a look at this? Thanks ??