Seeing different customing tabs in live previews.

I used my site server, SiteGround, to create a staged (copied) site for testing. In both the original site and in the staged site I installed the Sydney theme. When I do a live preview in each site Admin I see different tabs in the customizers. Why is that?
Example: original site
“General”
“Site Identity”
“Hero Area”
“Typography”
etc

In staged site:
“General”
“Header”
“Hero Area”
“Typography”
etc

I can’t find the Header customizer in the original site.
Also, the content of some tabs, like “Site Identity” is different. The one in the staged site has much more content and options, like Logo Height which is missing in the original site version.

Arrggg!