- Plesk for Linux
- Plesk for Windows
PHP settings or webmail are not changed to default ones, that are defined in service plan after its synchronization.
Permissions Hosting settings management and Common PHP settings management are enabled in the service plan. For webmail this behavior is defined by Ability to change mail settings.
Service plan with Hosting settings management and Common PHP settings management parameters enabled provides privilege that makes it possible for a subscriber to change PHP settings, and it's allocation is ignored during a sync, so that subscription remains synced with the plan even if value of the PHP setting in the subscription differs from the corresponding one in the plan.
More details are available in Plesk Administrator Guide
To restrict such an option and make PHP settings to be synced with ones specified in service plan, uncheck Hosting settings management, Common PHP settings management, Ability to change mail settings in Home > Service Plans > service_plan > Permissions tab.
For Plesk 17.5: now it is required to uncheck 'PHP version and handler management' if service plan was created with default permissions. To make changes persistent, refer to this KB: Additional PHP directives disappeared after synchronization with the service plan