Header 'RevenueCat-Swift.h' not found & Could not build Objective-C module 'RevenueCat' – Ios swift

I integrated RevenueCat into an app written in Swift and SwiftUI. It worked all well until now.
All of the sudden Xcode throws these two errors when building the app:

Could not build Objective-C module ‘RevenueCat’

At the import RevenueCat statement

Header ‘RevenueCat-Swift.h’ not found

In a modul.modulemap

The Content of the modulemap is as followed.

framework module RevenueCat {
  umbrella header "RevenueCat-umbrella.h"

  export *
  module * { export * }

}
 

module RevenueCat.Swift {
    header "RevenueCat-Swift.h"
    requires objc
}

The weird thing is, that after rebuilding the app once or twice, the errors disappear.
However, if I try to archive the app, they pop up every time and prevent Xcode from archiving the Build.

I updated to the lates Xcode version some days ago, beside that there’s nothing special that could point to the start of the problem.

Any Ideas on that?