Possible Turbo Tax software glitch on line 6b of 1040 regarding taxing social security benefits

I am reviewing my 1040 after having completed entering data and have noticed line 6b shows 0 for the taxable amount of my total social security income of $3240. 

I earned over 50k from a federal pension and I am wondering if this is a glitch in the TT software

I have read that if your total retirement income is over 44k SS income is taxable

Thanks for your help in clarifying this issue