C# async await (try/)catch fails in .NET 6

The following code works as expected in (the code-behind of a WPF UserControl of a .NET 4.8 project).

    private async Task DeleteAsync()
    {
        try
        {
            await ViewModel.DeleteAsync(GetSelectedItems());
        }
        catch (Exception ex)
        {
            var doCatch = ex is ValidationException
                || ex is ExpectedInfoException
                || ex is ExpectedDbException;
            if (doCatch)
                ExeptionHelper.HandleException(ex, AppConstants.ApplicationName);
            else
                throw;
        }
    }

The following analog experiment does not always Catch an exception in a .NET 6.0 project, see inline comments. My attempt of a minimal reproducible repro sample is still not complete yet, but hopefully someone already has an educated guess for the reason?

        private async void DeleteListAsync()
        {
            var list = ViewModel.GetSelectedItems(
                dataGrid.SelectedItems.OfType<ActorModel>().ToList());
            try
            {
                await ViewModel.DeleteListAsync(list);
            }
            catch (Exception ex) when (
                ex is ValidationException
                || ex is ExpectedInfoException
                || ex is ExpectedDbException)
            {
                /* this part does run as expected when() one of those three 
                 * custom MyNamespace.Exceptions gets thrown in the previous `try` block.
                 * But unexpectedly *not when thrown inside the nested step-into code of 
                 * ViewModel.DeleteListAsync() */
                ApplicationHelper.HandleException(ex, Intl.LocalizedConstants.AppName);
            }
            catch
            {
                /* this part does run as expected when a `new InvalidOperationException("Test")`
                 * or `NotImplementedException()` gets thrown directly in the `try`block.
                 * Also when thrown inside the nested step-into code of 
                 * ViewModel.DeleteListAsync() */
                throw;
            }
        }

[Solved]: Much later, with the help of the useful comments I actually found a missing await statement in a secluded and dark corner of the nested code, just as @Charlieface said, thank you all very much!