I’m nor able to change jevelin default logo… I go on Theme setting, Header, and than I insert 3 times my logo (150px x 150px png logo) but no result, the logo on my pages is always JEVELIN… in my admin panel I see my logo…
It seems from your shared screenshot that you are using header template created using the header builder so you can change the logo from header builder a shown in the attached screenshot.