Why is NSHostingView being laid out reentrantly?

    func zoomOne() {
        region.span.latitudeDelta = 10_000
        region.span.longitudeDelta = 10_000
    }
    
    func zoomIn() {
        region.span.latitudeDelta /= 2
        region.span.longitudeDelta /= 2
    }
    
    func zoomOut() {
        region.span.latitudeDelta *= 2
        region.span.longitudeDelta *= 2
    }

My MacOS app has three methods for adjusting the zoom on a MapKit map display. Each is tied to a separate view Button.

zoomIn() and zoomOut() work as expected, but when the program calls zoomOne(), Xcode breaks and reports a runtime issue in the Issue Navigator:

NSHostingView is being laid out reentrantly while rendering its SwiftUI content. This is not supported and the current layout pass will be skipped.

As a fix, I tried embedding the zoomOne() region update in a DispatchQueue.main.async closure, but it still failed with the same issue.

Thanks, Mark