SignalR client method calling C#/JS interop, hangs indefinitely.

    hubConnection.On("GetDimensions", async () =>
    {
        var dimensions = await _screenInfo.GetDimensions(); // THIS HANGS HERE, does JS stuff
        await hubConnection.SendAsync(
            "CalculateDisplayArea",
            dimensions.width,
            dimensions.height,
            0);
    });

    public async ValueTask<ScreenDimensions> GetDimensions()
    {
        if (_screenDimensions is not null)
        {
            return _screenDimensions;
        }

        // Load the module if null.
        _module ??= await _js.InvokeAsync<IJSObjectReference>("import", _dbModulePath);

        _screenDimensions = await _module.InvokeAsync<ScreenDimensions>("getDimensions");
        return _screenDimensions;
    }