I had the same problem in previous versions. It then went away after an upgrade. Now it is back on one of my sites but on others. I can't find any conflicts. I see you switched your contact form. I like Jetpack because it blocks spammers better than any other. I hate using captcha, akismet is the best.
If anyone knows anything I'm looking for answers as well.
Here is my page [ contact page redacted support is offered via the forums and not email ]
I have also tried it without sidbars to no avail. When I go to edit the form it also pulls up a single page instead of the layer view like it normally does.