Why does ty21 start by owing money to the IRS directly after importing ty20?

1. Install TT21
2. Import TY20 to initialize TY21.
3. I owe money to the IRS. 
   1. I expected to start with $0, like in previous years. 
4. Where can I look in TT21 to explain why I'm starting out owing money by default?
   1. Last years return (and refund) should have brought me back to zero, correct? 
   2. i.e. Before a user adds any information which will affect their return for the upcoming tax year, you would expect them to start from zero, correct? 
5. Is there something special about this tax year that would cause this?
   1. Some extraordinary tax consequence due to changes in the law or the pandemic or something?
   2. Again, is there some section of the program that I can look at to verify or explain this? 

Thanks in advance!