I'm watching this in case you find a solution as I am having the same issue. I've only seen it on one page so far -- where I have a front-end form. WP Discuz shouldn't even be on this page as for the "page" post type I only have forms showing on specific pages and this isn't one of them. I'm sure it does have something to do with the tinymce editor as it's only showing on pages with the rich text editor.
The issue will be fixed in the upcoming update of the wpDiscuz plugin. No ETA yet.
In case you want to say thank you! 🙂 We'd really appreciate if you leave a good review on the plugin page. This is the best way to say thank you to this project and the support team.