OSX: Wrong theme icons are loaded when app is deployed with macdeployqt

I'm using custom icon themes for QOwnNotes (https://github.com/pbek/QOwnNotes).
In dark mode I set a theme breeze-dark-qownnotes (https://github.com/pbek/QOwnNotes/tree/develop/src/icons/breeze-dark-qownnotes) with `QIcon::setThemeName("breeze-dark-qownnotes")`.
Here is the icon resource file: https://github.com/pbek/QOwnNotes/blob/develop/src/breeze-dark-qownnotes.qrc

That works perfectly under Linux and Windows.

When I build with `qmake` under OS X it still works perfectly. But when I use `macdeployqt QOwnNotes.app` to finally deploy the app the icons from the dark mode theme are not used anymore. Instead the icons from the default icon set breeze-qownnotes (https://github.com/pbek/QOwnNotes/tree/develop/src/icons/breeze-qownnotes) are viewed in the toolbar and everywhere else.
Here is the default icon resource file: breeze-qownnotes.qrc (https://github.com/pbek/QOwnNotes/blob/develop/src/breeze-qownnotes.qrc)