Azure Traffic Manager will stop automatically enabling, disabling, or deleting endpoints for Azure Cloud Services on May 1, 2019

Currently, Azure Traffic Manager can automatically enable, disable, or delete endpoints when starting, stopping, or deleting the corresponding cloud service. However, this option will be retired on May 1, 2019, and you’ll need to manually enable, disable, or delete profile endpoints in Traffic Manager when starting, stopping, or deleting a cloud service. You’ll continue to be billed for the endpoints unless they are manually disabled or deleted.
Source: Azure Roadmap