Can't add image to blog post (dialog box behind Edit Gallery box)

I'm having a continued problem with not being able to add images to a blog post because it opens the dialog box to add an image behind the dialog box to edit the post.  If I click on the Add Image dialog box, it will prompt to save/discard the changes to the rest of the blog post. What can I do? I've tried in all 3 browsers here and it's the same result (Edge, Firefox, Chrome on PC).