PHP does not apply

[AcidLava]

Hello,

On Prestashop 1.7.1.2, I am trying to switch the store to PHP 7.1.

I have applied this PHP version to my OVH Web Cloud hosting, but PHP remains at 7.0 as indicated in Advanced Settings -> Information. At this point, I have:

-  Verified the .ovhconfig file at the root of the hosting.

- Checked that no other .ovhconfig file is present in any directory.

 - Regenerated the .htaccess file.

- Executed the following commands via SSH:

php -v alias php='/usr/local/php7.1/bin/php'

When I add a phpinfo.php file at the root of the store and set permissions to 644, I get a "The page you are looking for cannot be found." message via mydomain.com/phpinfo.php (a recurring error on my side regardless of the environment).

Nothing works, which prevents me from installing the 1-Click Upgrade module that requires PHP 7.1. I wonder if this might simply be a bug with the store.