I’ve been seeing the same thing, and can even give an exact time when it started. I have a bot that uses the Perl POE framework for IRC and Twitch API connections, and since 10:45 PM EST on January 21st nearly every (there have been a few that succeeded) request to the /streams/:channel endpoint has failed with an empty response as the OP is describing. I haven’t seen any evidence of a timeout, just a connection error and empty response. There have been 503 (service unavailable, most recently with “Backend server is at capacity”) and 500 (internal server error) responses as well.
I call /streams/:channel (detection of my own streaming) and /channels/:channel/follows (new follower detection) once a minute, and (when I’m offline, as it’s part of my auto-host system) /streams at most once every 3 minutes. The latter 2 sometimes fail for similar reasons, but they don’t get anywhere close to the “nearly every request” failure rate that I’m seeing with the first one. With that calling frequency, it’s hard to believe I’m being rate limited, and even then I’d expect to get a non-empty response.
Unfortunately, with Perl POE, I’m not sure how to check for any SSL issues. There is a debug switch in its HTTP client, but that doesn’t report anything at all about SSL, success or failure.