When I receive a text message on my phone, my smartwatch used to receive one notification. The watch would buzz once, and the Verizon Messages notification would come up over top of older notification cards. Now, I will usually receive three notifications on my smartwatch for every text message. The watch will vibrate three times, and the notification card will disappear and reappear, often appearing underneath older notification cards, so as not to be easily seen. No other app does this. This problem has occurred when the Moto 360 was synced with my old Samsung Galaxy S6, and now with my unlocked Pixel XL.
Smartwatch: Moto 360 (v2), running Android 6.0.1, Android Wear 1.5.0.3336103
Smartphone: Google Pixel XL, unlocked, running Android 7.1