Yes, the bug is back. A code-H Form 1099-R a blank box 2a and box 2b Taxable amount not determined marked is being erroneously treated as taxable.
Note, however, a code-H Form 1099-R wit a blank box 2a and box 2b Taxable amount not determined marked is a Form 1099-R that has been prepared incorrectly by the payer. Code H means that the distribution is unconditionally nontaxable, so box 2b Taxable amount not determined should never be marked on a code-H Form 1099-R.
Assuming that this truly was a rollover to a Roth IRA from a designated Roth account in an employer's qualified retirement plan and the code H is the correct code for the distribution, my recommendation is to leave box 2b Taxable amount not determined unmarked on TurboTax's 1099-R form when the code in box 7 is H.
