How do I get default values to appear in MudBlazor MudSelect with MultiSelection="true"?

I'm using MudBlazor to create a component to select multiple items in a MudSelect. When I pre-populate values they don't appear in the select control. When the control is expanded the correct items are indicated as selected. If I modify the selection they do show. If I close the expansion without making changes they don't.

I need them to show on the initial state.

Video: https://share.clickup.com/clip/p/t1280802/25e76e23-189d-4696-a795-8640b31a798f/screen-recording-2021-03-30-09%3A52.webm

I have a code demo here: https://try.mudblazor.com/snippet/mEmPkHHkpwkPNrkt

__Main.razor:

@using BlazorRepl.UserComponents

<MyComponent Config="MyLocations" 
    OnConfigChanged="LocationsChanged"></MyComponent>

@code {
    private List<Location> MyLocations;
    private List<Location> ModifiedLocations;

    protected override async Task OnInitializedAsync()
    {
        await base.OnInitializedAsync();
        MyLocations = new List<Location>() {Location.inside, Location.underwater};
    }

    private void LocationsChanged(List<Location> val)
    {
        ModifiedLocations = val;
    }
}

MyComponent.razor:

@using BlazorRepl.UserComponents

<MudPaper Elevation="3">
    <MudSelect Label="Locations" SelectedValues="new HashSet<Location>(Config)"
        T="Location" MultiSelection="true" >
        @foreach (Location val in Enum.GetValues(typeof(Location)))
        {
            <MudSelectItem Value="val" />
        }
    </MudSelect>
</MudPaper>

@code {
    [Parameter] public List<Location> Config {get; set;}
    [Parameter] public EventCallback<List<Location>> OnConfigChanged {get; set;}

    private void SelectedValuesChanged(HashSet<Location> val) {
        var v = new List<Location>(val);
        if (!Utilities.EnumListEquals(v, Config))
        {
            Config = v;
            OnConfigChanged.InvokeAsync(Config);
        }        
    }
}

stuff.cs:

namespace BlazorRepl.UserComponents
{
    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;

    public static class Utilities {
        public static bool EnumListEquals<T>(List<T> one, List<T> two) where T : struct, IConvertible
        {
            if (!typeof(T).IsEnum)
            {
                throw new ArgumentException("T must be an enumerated type");
            }
            return (one.Count() == two.Count() &&
                    one.Count(two.Contains) == two.Count());
        }
    }

    public enum Location { inside, outside, underwater }
}