Cannot connect to Redis Labs from C#

Question

I recently set up a Redis instance on Redis Labs, and wrote this code to connect:

using StackExchange.Redis;

var redis = ConnectionMultiplexer.Connect(
            ConfigurationOptions.Parse(
                "<my-redis.instance>.east-us-mz.azure.cloud.redislabs.com:19671,password=<password>,ssl=True,abortConnect=False"));

var db = redis.GetDatabase();
var pong = await db.PingAsync();
Console.WriteLine(pong);

I get the error

StackExchange.Redis.RedisTimeoutException: 'The timeout was reached before the message could be written to the output buffer, and it was not sent, command=PING, timeout: 5000, inst: 0, qu: 0, qs: 0, aw: False, bw: CheckingForTimeout, rs: NotStarted, ws: Initializing, in: 0, serverEndpoint: <my-redis.instance>.east-us-mz.azure.cloud.redislabs.com:19671, mc: 1/1/0, mgr: 10 of 10 available, clientName: SVEN-OMEN(SE.Redis-v2.5.61.22961), IOCP: (Busy=0,Free=1000,Min=16,Max=1000), WORKER: (Busy=1,Free=32766,Min=16,Max=32767), POOL: (Threads=12,QueuedItems=0,CompletedItems=72), v: 2.5.61.22961 (Please take a look at this article for some common client-side issues that can cause timeouts: https://stackexchange.github.io/StackExchange.Redis/Timeouts)

Seems simple enough, but anyone familiar with connecting to this service: Does this look like a code or Labs configuration issue?