I'm managing a Centos 7.7 server with apache 2.4 working fine so far. I hace SSL configured and running, and all my pages are served without problem (all of them through https). Now I have to run a site which is badly coded and doesn't show correctly through https, because mixed content errors block css. The problem is that http is not working, there is a 301 Redirect to https that I'm unable to find in the configuration files. There are no Rewrites, Redirects or ProxyPass in the configuration files (grep -r Rewrite or Redirect in apache directory couldn't find anything), except this ones:

ProxyPassMatch ^/foo/(.*.php)$ fcgi://127.0.0.1:9000/mnt/data/foo/$1  
ProxyPassMatch ^/foo2/(.*.php)$ fcgi://127.0.0.1:9000/mnt/data/foo2/

for using php7 only for this sites. I have a default:443 and a default:80 VirtualHost and I cannot see anything strange. Also I checked firewalld in case there is a Port redirection, whith no luck. Any idea? Thanks in advance.