SwiftUI TextSelection crash on macOS

Using Swift
1

I have a very simple SwiftUI app, works fine on iOS, crashes on macOS:

struct ContentView: View 
{
	@State var testStr: String = ""  		
	@State var selection: TextSelection? = nil
	
    var body: some View 
	{
        VStack 
		{
			TextField("Test", text: $testStr, selection: $selection)  
			.onChange(of: selection) {print("selection changed")}
        }
        .padding()
    }
}

• Start app, write something in the TextField and move the cursor around.
iOS: "selection changed"
Mac: nothing (Bug ?)

• double click on some word
both Mac and iOS: "selection changed"

• write some more in the TextField
iOS: selection changed
Mac: crash

Any idea what I am doing wrong?

Gerriet.

Xcode prints:

*** +[NSSelectionArray newWithArray:]: no ranges
(
	0   CoreFoundation    0x000000019b770ec0 __exceptionPreprocess + 176
	1   libobjc.A.dylib   0x000000019b256cd8 objc_exception_throw + 88
	2   CoreFoundation    0x000000019b770db0 +[NSException exceptionWithName:reason:userInfo:] + 0
	3   AppKit            0x000000019f38138c +[NSSelectionArray newWithArray:] + 196
	4   AppKit            0x000000019f3812b0 +[NSSelectionArray arrayWithArray:] + 16
	5   AppKit            0x000000019f38110c -[NSTextView(NSSharing) _fixedSelectionRangesForRanges:affinity:] + 56
	6   AppKit            0x000000019f3804a4 -[NSTextView(NSSharing) setSelectedRanges:affinity:stillSelecting:] + 348
	...
)