I was also simply not having the Versa vibrate when a notification would come through. All notifications were on the Versa (as long as I looked for them), just no vibration alerting me. I would, though, get the vibration when a phone call would come through, just not with text messages or app notifications. I tried all the basic/non-intrusive stuff, like simply Forget This Device in bluetooth settings, etc. But, here is what did work for me.
I simply removed the Versa from the Fitbit app, and then added it back in. Aaaaaaand the vibrations returned (for now anyway...we'll see if it lasts). Of course, the sucky part is, is that now all the apps that I added are no longer there, and it's a "process" to add them back. While this sucks, at least it is working correctly. Phone call notification works, app notification works, text and calendar notification works...including the vibration alert on Versa for all notifications.
I do have the latest Fitbit app, the most recent Versa firmware, and the latest iOS 13.1.2 on my iPhone SE.
Hope this helps!
