ClientWebSocket hangs on ReceiveAsync, never continues

try
{
    var node = await restClient.ApiClient.QueryNodeAsync(cancellationToken);
    await _ws.ConnectAsync(new Uri(node.Ws), cancellationToken);
    var model = new AuthenticateSendEventApiModel(token.RawToken);

    using (var stream = new MemoryStream())
    using (var writer = new StreamWriter(stream) {AutoFlush = true})
    {
        var json = JsonConvert.SerializeObject(model);
        await writer.WriteAsync(json);
        await _ws.SendAsync(stream.ToArray(), cancellationToken);
    }

    var stream2 = await _ws.ReceiveAsync(cancellationToken); // hangs here
    logger.LogInformation("Length: {Length}", stream2.Length);
}
catch (Exception ex)
{
    logger.LogError(ex, "Failed");
}