Retirement tax questions

I am a retired 77 yr. Old educator.  I have lived in pa. For over 20 years.  I collect a pension and social security.  While doing my pa. Taxes , the computer shows I owe over $2000.00 in Pennsylvania taxes…. This is a state that doesn’t tax seniors who live in Pa.  Last year I paid under $20.00 what’s going on  I’m using Turbotax