When parameters for a subscription in Plesk have been modified, Plesk may lock them. This means that when a change is made to the service plan itself, locked subscriptions are not updated by default.
To unlock subscriptions and re-integrate them into the service plan, head over to the subscription in question (from the Subscriptions list in Service Provider View), then on the right hand side find the widget that reads Account.
At the bottom, there’s an “unlock and sync” option. Click that and the subscription will be unlocked and synced with the service plan it was once part of.
Why are subscriptions locked in the first place?
Good question! One example is this: imagine you had a specific version of PHP as the default on your service plan. Say PHP 7.2. But then, some subscriptions use content that’s not compatible with that version of PHP and instead require version 5.6. No trouble, you’ll just change it in that particular subscription and all is well.
Until you decide that some other parameter needs to be changed on that service plan – say the amount of webspace or the number of databases. If you were to sync all subscriptions on that plan with the new default parameters, then the default version of PHP would also be synced and set to 7.2 – which would break the subscription’s content and make one of your customers unhappy.
Locking a subscription means this subscription is “exempt” from syncing, which means all other subscriptions can get the new parameter, leaving you to deal with the locked subscription individually (and – more importantly – without breaking it).