httpd-vhosts.conf problem

I am already installing nginx, varnish, apache on my server and my "httpd-vhosts.conf" listen on port 8081,443

In sentora > apache config > apache port I sent port to 8081,

everything is ok but somethimes my "httpd-vhosts.conf" listen ports change from 8081,443 to 80,443
how I can stop automatically port changing and keep my ports :/
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