while I understand that in 2018 you itemized, did you hit the $10,000 limit of SALT (state and local tax) deductions? There are byzantine rules to determine whether the state refund is taxable THIS year if you hit the SALT limit LAST year.
So even if you itemized last year, it is possible that the state refund is not taxable this year
look at the form called "st refund wks". It's in the desktop version which goes through all the math; not sure what is provided in the online version.
