In my TurboTax Desktop test return, I have an amount on Missouri Form MO-A, Line 18, which transferred to Missouri Form 1040, Line 4.
Do you see your Public Pension amounts on Lines 1, 2, 4 and 5 on Form MO-A?
If not, go back to your 1099-R entry in your Federal return to be sure you indicated you had a Public Pension, which should resolve your issue.
@gail60