The reason I didn't question this 2 years ago was I was suffering from severe depression for a number of years and my MD had put me on new meds a year before. And I didn't realize that I was having strange side effects from the drugs. I went away to my home country for a year since then, stopped my meds until things cleared up and returned recently. I'm a lot more with it now and have realized the strange discrepancy in the tax paid in 2019.
Still not enough ... is the 2019 tax on one line only ? Or is it a combination of multiple lines ? Was this a year when you did not claim dependents ? Were there credits (or lack of them) involved ? Actually the 2019 year is the only one making sense right now.
I highly suggest you talk to someone in person locally as figuring this out on a forum is not the most effective method.
Don't know if TT support will be any help but you can try them ... contact details can be found here