Safari admin menus disappear

I love this plugin! The only problem is that in Safari on the Mac, right after the page finishes loading, the menu and admin bar disappear. Moving the mouse over any active element on the page will make them reappear (even mousing over them in the inspector).

Any chance this can be fixed? I’m not a front end developer, but I can debug in a browser if that helps.

Latest Safari, latest macOS, no plugins. This doesn’t happen in Chrome of Firefox on the same Mac.