I followed the steps on turbotax doc for backdoor roth conversion and fed refund is good (no extra taxes). Why is my MA state refund going down when I enter my 1099-R?

I did a backdoor roth conversion in 2020. I immediately converted it and had no other traditional IRAs so technically there should not be any tax liability. I entered 1099-R in turbotax as per the instructions. Federal refund did not get affected which is what I had expected but MA state refund is going down by a couple of hundred dollars. Cannot understand why. Please help!!!