Thank you for your quick response. I double checked the 1099R and the amount is only entered once. The reason I now think this is a Turbotax error is that I had worked on my 2018 return in July and set it aside. At that time the taxable IRA was correct and showed 1/3 of the total in line 4b. I made a pdf of the tax return and set it aside. I restarted working on it in late august, Turbotax made some automatic software updates and then the numbers dramatically changed (i.e. 1 and 1/3 of IRA showing on line 4b), my refund dropped considerably. The only thing that seems to work is if I delete the 1099R and manually enter the IRA amount in form 8915B.
