Question Grey line in upper left corner of template I inserted

[RickyO]

Started a new test site locally. Installed E and E-Pro (licensed). Created a Welcome page with the E Canvas template option. I have a grey line in the upper left corner of the page. It appears to be related to the WP editor, but can't tell for sure. When I switch to editing with E, the line persists. I placed the About-Startup-Page E template, and the gray line is still there.

Using WP 5.0 on XAMPP-win32-7.30-0, E-Pro 2.3.1 on Win10-Pro

What did I miss along the way???

 

[RickyO]

With a little testing, it appears to be unique to the Elementor Basic Heading Element. What would be so unique about that one? And why is that line there?

Thanks in advance.