Why is it telling me I have a tax liability from 2019

That is just the Total Tax on your income from 2019, not your refund or tax due.  It just looks at your 2019 tax to see if you have an exception to the penalty by paying in as much withholding for 2020 as the tax liability on your 2019 return. Even if you have a refund on your 2020 return you can still owe a penalty for not having enough withholding taken out or by not paying in evenly during the year.

If you do not pay enough tax for 2020, you may have to pay a penalty for underpayment of estimated tax. Even if you are getting a refund you can still owe a penalty for not paying in evenly during the year. Generally most taxpayers will avoid this penalty if they owe less than $1,000 in tax after subtracting their withholdings and credits, or if they paid at least 90% of the tax for the current year, or 100% of the tax shown on the return for the prior year, whichever is smaller.