Mine did too. I thought it might be due to being close to the limit on internal storage space. I went ahead and ordered the 64GB model when it was on sale last week, set it up yesterday, and it is running smoother than my 32GB model. However, it is the Android One version so it is even more streamlined than the regular model and does not have all of the Moto features so that may be why.
I'm going to use the 64GB as my daily phone now but will probably do a full reset on my 32GB and see what happens.