
VladimirB.45940 (Customer) asked a question.
I had to update expired Security certificate. On My screen, security certificate has correct expiration date. All mt DNS related entries had been propagated with AWS Rty53 for over a year. What is going on? I have dead website for 3 days. I am on the free-tier, so I can't open support ticket, yet this is clearly tech support issue.

@Paul S. (Okta, Inc.) Thank you for point me out into correct direction. Here is solution:
For whatever reason, why CNAME pointing to AWS EC2 instance did work for almost two years until this weekend is beyond me. I am not an infrastructure developer. I hope that this answer helps someone.