[Plugin: TinyMCE Excerpt] conflict with media library

When I have TinyMCE Excerpt activated all my image captions have unwanted <p> tags automatically inserted as part of the caption text.
If I deactivate it I can remove them and they stay gone. Unfortunately this makes the plugin unusable for me at the moment as it will confuse my clients if this happens.

https://www.ads-software.com/extend/plugins/tinymce-excerpt/