There is nothing to fix.
It is not an excuse, it is the published IRS 1099-R form rules. TurboTax has no control (or even cares) if a financial institution does not follow the IRS 1099-R instructions, TurboTax does and will flag an error when an illegal value is in box 9a, as it should. If you want to complain, then complain to the company that violated the rules, not the one that follows them.
There is only an entry on 9b if the distribution is split between two or more persons then the percentage that the person on the 1099-R is receiving is in the box. Zero is not a valid entry.
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**
