Device Type Handlers are in the process of being migrated to Edge drivers as ST is phasing old the legacy groovy architecture of the platform. I assume the device has been migrated to an Edge driver. Use the new web interface Adnaced Wep App to check your device (or ST app, open device, tap on 3 dots and if you see Driver in the list, it is now using an Edge driver). If you do not see DTH listed in Advances Web app… it is using an Edge driver.
to resolve, enroll the following community developed Edge driver (https://community.smartthings.com/t/edge-driver-mc-z-wave-edge-drivers-and-others-with-fibaro-devices/239409 onto your hub and switch the device to this Edge driver and not the stock one that it is probably using now. After you enroll the driver on your hub, open the device in the St app (3 dots and Driver) or use the Advanced Web app to switch the driver.
check out this thread: https://community.smartthings.com/t/child-device-not-working/265954