A couple things to try.
1) If you uploaded a picture or a PDF file....that leads to all kinds of errors in the form that you may not see...so delete that 1099-R form entirely, then re-enter it manually.
Another thing to try (if you already haven't)
2) Make sure the box 2a value is copied into box 16 (or the federally taxable amount of box 1 if box 2a is empty or "undetermined" usually that's just box 1). If box 14 has no $$ amount in it, make sure it is entirely empty...no text, no zero.
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Beyond that, try Customer Support.
How do I contact TurboTax?