I am also having the same issue. I can post images from my WP Media Library just fine, and the post shows up as well but there is no gallery (just a blank white box where they should be). Also, when I insert my select GMedia Gallery into my post, it shows as [gmedia id=1] but no gallery is visible in the preview.
Here is the link to my post: https://kinkiepink.com/blog/
Any help you can provide would be greatly appreciated.
Respectfully,
–Ivan