Are you getting any errors in your browser console or php error_log file?
I have released that the problem is about "http" & "https". My admin URL is starting with https. When I look at the corner of the browser, I see a security shield icon.
When I move the mouse over the icon, I see "This page is trying to load scripts from unauthenticated sources" There is option Load unsafe links/scripts.". Here is the detailed page about the problem. https://support.google.com/chrome/answer/1342714