Demo code created with

dotnet new maui -f net8.0 -n demo

The demo.csproj was edited to remove some targets other than net8.0-maccatalyst

In MainPage.xaml.cs, OnCounterClicked is changed to

private async void OnCounterClicked(object sender, EventArgs e)

with

var file = await FilePicker.Default.PickAsync();

added to the end of that method.

Environment

1. MacOS 15 (Sequoia)
2. Xcode 16. Behaviour present with Xcode 15.4 manually installed.
3. Checked with project templates generated against Microsoft.NETCore.App 8.0.8 and 9.0.0-rc.1.24431.7

Expected behaviour

Dialog box shows up to select a file when button clicked.

Actual behaviour

Nothing shows up once button is clicked, and buttons lose responsiveness.