Redirect www to non-www on Nginx gives me 400 bad request

I'm trying to redirect all www to non-www domain address. I have installed my LetsEncrypt SSL for non-www domain. non-www domains are working fine. I have configured www to non-www redirection on my Nginx running on Ubuntu server. I have encountered a strange problem.

On Windows Firefox and Mac Safari browser, will redirect to and it says it's a suspicious domain and I need to add exception to proceed. It looks...

Redirect www to non-www on Nginx gives me 400 bad request WordPress ...