there are known issues with improper display of menus on an external display when using retina macbooks.
A build using gtk3 3.24.38 doesn’t show this behaviour - but has redrawing issues. Since the latter is just annoying and can be handled by additional scaling attempts (if it occurs) using gtk3 3.24.38 seems to be the better solution.
so here a 10.14 x86_64 release build with gtk3 3.24.38
darktable-4.4.2_x86_64_gtk3.24.38.dmg
not codesigned, so you might need to allow execution via terminal: xattr -c <path/to/application.app>