Internet cannot display the website

Hi-
This problem started about 2 months ago. My computer doesn't open https://anthem.com
So far it's the only website that I can't open.

I've noticed that if I use "https" it won't open, but if I use "http" it does.

I tried opening it using safari on the same computer and I was able to open the "https" without any problem.

I tried opening https on a different computer and, again, no problem.

It seems that it's just a problem with my computer in particular. What can I do to fix the problem?

Thanks!