The causes of this problem vary by scenarios.
The agent status is Offline or Not installed in the server list on the Web Tamper Protection page.
Rectify the fault by following the instructions provided in How Do I Fix an Abnormal Agent. Ensure that Agent Status in the server list is Online.
Protection Status is Enabled in the server list on the HSS console.
HSS editions include the enterprise, premium, and WTP editions. Before enabling WTP for a server, ensure that enterprise, or premium edition HSS has been disabled for the server.
To enable WTP, choose Web Tamper Protection > Servers.
If you have applied for the WTP edition, you can use all functions of the premium edition, and you can enable the server protection only on the Web Tamper Protection. After WTP is enabled, server protection of the premium edition is also enabled.