This is interesting. I assumed it has something to do with my Swift Packages used and embedded by the Objective-C frameworks. But this seams not to be the case. By the way, flagging your reply as "accepted solutions" was an "accident" on my part. But there seams to be now way to un-flag a reply once it has been set. So from my point of view, I'm still looking for an answer!

Thank you for the details! But no luck so far.

That's good news! I will adjust my workflow accordingly and test it with the new macOS beta.

Thank you very much for your feedback! What do I do if I have to support macOS 12 and can't use LocalizedStringResource (macOS 13.0+)?

Many thanks for the clarification!