Inline edit boxes not saving code

When trying to add inline css or js code via the pop-up light boxes, when they are closed, the code is not saved and the inline box becomes unusable. After entering inline code and doing a save, when reopening the inline editor box, it is just a blank white lightbox with no text field. Any ideas what the issue could be?

Note: Code works if added as an uploaded file.

https://ww.wp.xz.cn/plugins/specific-files-for-posts-and-pages/