A code-G Form 1099-R reports a distribution from a traditional 401(k) account, not from a Roth 401(k) account. A Form 1099-R reporting a distribution from a Roth 401(k) that was rolled over to a Roth IRA would have code B or code H. Either your rollover was not from a designated Roth account in the 401(k) or the plan issued an erroneous Form 1099-R.
