I’ve read this reported elsewhere and it was a macOS controlled item, not a Gramps option. Can’t remember where it was posted. (Not being a mac user for about a decade, I tend to only skim macOS specific issues.)
The following page looks promising…
Tutorial to keep menu bar from disappearing on Mac Monterey, Big Sur, Catalina or Mojave, including making Mac show menu bar in fullscreen.
And you might want to read:
Gramps 5.1.1 - iMac Ventura 13.2.1
Ever since moving to a new Mac, my Gramps software only opens in full screen.
Unfortunately, for around half the times it opens, the “Exit Full Screen” button is not visible. Nor is the Toolbar above it. I have to force close Gramps and try again.
The “save on exit” Gramps settings option is always on and I never close with a full screen view. Yet it always opens in full screen view.
I have not yet found a default setting in Gramps or Safari that specifies …