The `File` menu is a bog standard GTK menu, nothing special there. Perhaps the other GTK apps you use are GTK3, but AFAIK Debian still only provides Geany GTK2, check `Help->Debug Messages` near the top.
If you can build Geany from source you can configure it with `--enable-gtk3` and try that. -- You are receiving this because you are subscribed to this thread. Reply to this email directly or view it on GitHub: https://github.com/geany/geany/issues/1668#issuecomment-340570791
