Xcode 13.3 wrongly claiming UI changes on background thread

My App had no such warnings before updating to 13.3, but now it claims I'm updating from a background thread. A simple print will make these warnings stop, so something is wrong:

 @MainActor private func runOnMain(_ action: @escaping () async -> ()) async {

        //print("", terminator: "")

        await action()

    }

simply uncommenting that print() makes all the warnings go away, so I think 13.3 has an issue here... Is anyone else seeing this?

Replies

Change to:

@MainActor 
private func runOnMain(_ action: @escaping ()) async {
    action()
}

or

@MainActor 
private func runOnMain(_ action: @escaping () -> async Void) async {
    Task { @MainActor in action() }
}