It's getting a 502 Proxy error which means the entire authentication server is just down. It may be because the server registered the recent 27k users trying to log in at the same time as an DDoS attack or just simply overwhelmed. To me this just shows how ill prepared cic is when they handed out this many ITA at once.
Also guys you can check with this site to see what people are sharing. Mostly people saying the same thing but maybe it will bring people some peace> https://www.isitdownrightnow.com/cic.gc.ca.html
ITA 26th November 2020
AOR 19th January 2021
Ghost Update 1 - 9th Feb 2021 (No Change)
Email Update 1 - 10th Feb 2021 (No Change)
Medical: 16-03-2021 (will upload via Webform)