we have none of your tax info to determine why there was a penalty and you shouldn't post it on this public forum. I have provided a link to IRS form 2210 which is used to calculate the penalty. TT doesn't prepare a 2210 when the simplified method is used.
here are the rules
(B)Required annual payment
For purposes of subparagraph (A), the term “required annual payment” means the lesser of—
(i)90 percent of the tax shown on the return for the taxable year (or, if no return is filed, 90 percent of the tax for such year), or
(ii)100 percent of the tax shown on the return of the individual for the preceding taxable year.
Clause (ii) shall not apply if the preceding taxable year was not a taxable year of 12 months or if the individual did not file a return for such preceding taxable year.
(C)Limitation on use of preceding year’s tax (for line 8 of form 2210)
(i)In general
If the adjusted gross income shown on the return of the individual for the preceding taxable year beginning in any calendar year exceeds $150,000, clause (ii) of subparagraph (B) shall be applied by substituting “110 percent” for “100 percent”.
even if you meet these tests there can be a penalty if you made untimely estimated tax payments. they were due 4/15/19, 6/15/19, 9/15/19, 1/15/20
https://www.irs.gov/pub/irs-pdf/f2210.pdf
