2018 tax changed for state (NY)

Last year - 2018 - I used Turbotax Deluxe to file Federal and state (New York) taxes.  Turbotax determined that I owed New York $355., which I paid.

This year, while working with Turbotax on 2019 taxes, I wanted to check some entries for 2018 for comparison purposes and found much to my surprise that Turbotax now showed that New York owed me a refund of $362 on my 2018 taxes.  Federal taxes did not change.

What happened?  Why did Turbotax not notify me if there were changes?  Do I now file an amended return with NY to obtain the 2018 refund?

Any help will be greatly appreciated.