New resource rate was added to the service plan. After synchronization with existing subscription resource appeared in the subscriptions, but in the unmanageable status "Purchased".
The issue is caused by the bug with id #PBA-64233 ("Resource is added in "Purchased" status when subscription synced with "Install into Provisioning System" set to "Not Install"").
- Delete the resource rate added from the plans
- Synchronize the subscriptions with option "Remove obsolete resources"
- Add the resource rate back
- Synchronize the subscriptions with option "Install new resource(s)" and "Install into Provisioning System" set to "Immediately". It is important to set an option to "Immediately" to avoid the resources in the status Purchased due to the bug #PBA-64233.