Communications.makeWebRequest started returning 404 (did https requirements change?)

Hello, Communications.makeWebRequest started returning code 404 for all request, but the same code was working 2 days ago.
Did something change in Garmin's HTTPS requirements?

The following now fails both in simulator and in iOS:

Communications.makeWebRequest("https://pwys.tmskfk.com/", params, options, method(:onReceive));

Here's a SSL labs analysis with green A for a same url though:
https://www.ssllabs.com/ssltest/anal...wys.tmskfk.com

Any advice?

As the https request must pass Apple's guidelines, I have nginx configured according to this guide http://mattjay.github.io/2015/09/17/ios-9-TLS-requirements-and-nginx/ and I use letsencrypt's free https certificate.