Why suddenly http began to be redirected to https?

Question

Apache HTTP Server

There is a home Ubuntu server, sites are spinning on it. Today, all of a sudden, all sites began to redirect to an address with https. For example, I enter site1.loc into the address bar and redirects to https://site1.loc/mail to the page with RoundCube mail. Same with http://site2.loc, http://site3.loc... What's broken? How to fix?

Answer 1

decided everything. It turned out that somehow the place on port 80 was occupied by nginx, killed it, removed it from autoload, apache started to give sites normally.

Answer 2

Browser plugins, the same HTTPS Everywhere.