Complete strict concurrency checking fails to catch MainActor isolated init in an enum with associated value

[tareksabry1337]

Reproduction

enum GestureType {
    case tap(UITapGestureRecognizer = .init())
    case swipe(UISwipeGestureRecognizer = .init())
    case longPress(UILongPressGestureRecognizer = .init())
    case pan(UIPanGestureRecognizer = .init())
    case pinch(UIPinchGestureRecognizer = .init())
    case edge(UIScreenEdgePanGestureRecognizer = .init())
    
    func gestureRecognizer() -> UIGestureRecognizer {
        switch self {
        case .tap(let tapGesture):
            return tapGesture
            
        case .swipe(let swipeGesture):
            return swipeGesture
            
        case .longPress(let longPressGesture):
            return longPressGesture
            
        case .pan(let panGesture):
            return panGesture
            
        case .pinch(let pinchGesture):
            return pinchGesture
            
        case .edge(let edgePanGesture):
            return edgePanGesture
        }
    }
}

Expected behavior

The compiler should show a clear error message on where exactly the issue is, but it doesn't, it only shows an ambiguous error message

On a more complicated projects, the error shows up on each and every file.

Removing .init() compiles successfully, Also marking GestureType as @mainactor doesn't help

Environment

swift-driver version: 1.115 Apple Swift version 6.0 (swiftlang-6.0.0.9.10 clang-1600.0.26.2)
Target: arm64-apple-macosx14.0