LTE Galaxy Watch Will not Vibrate with incoming external notifications

[ahaxton]

I have an LTE Galaxy Watch and Samsung Galaxy S9+ operating on T-Mobile. About a week ago, watch notifications stopped making the watch vibrate. The motor still works, because it still vibrates when, say, it needs to remind me to get moving, but if I get a GMail, text message, news alert, etc the notification dot shows up but it does not vibrate.

• Neither Goodnight Mode nor Theater Mode are on.
• All apps are set to receive notifications.
• I have reset the watch.
• I have uninstalled the Galaxy Wearable app and reinstalled it (which reset the watch a second time).

Any ideas?