Good call on the transformer, and I appreciate the update about that, too. 
That makes me think of another recent topic where someone described measuring 16 V from an old 10 V transformer. In that case, the apparent power output for that transformer was rated for only 5 VA, which is below Wyze’s recommendation. I don’t know what your original transformer rating was, but I imagine you’ll have much better results with the newer transformer (and doorbell).