Can't change PHP version


I have PHP 5.6, 7.0 and 7.1 installed on Virtualmin (Debian 8).
I have choose version 5.6 for a subdomain but phpinfo shows 7.0 no matter what I do at Server Configuration -> PHP Versions.

Is there a way to directly edit the apache2 conf to set the PHP version for a domain or subdomain on Virtualmin?