TT's 1040 line 11b for 2019 shows taxable income of $47,371 ( married filing jointly ). line 12a & 12b tax shows $5,257 but I calculate it $5,296.52. Which is right?

Probably the TTX calc.

You are likely just using the tax tables....but the tax tables alone aren't used if you had any $$ in boxes 1a,1b, or 2a of a 1099-DIV form, or any other long-term capital gains on brokerage transactions.  Special calcs. are used since those other types of income are taxed at lower rates,or not at all.. 

Yes, your explanation fits my situation and is undoubtedly the answer!  Thanks for the quick response!! Much appreciated.

thanks,. I was looking up for same question and your answer helped me figure it out