AndrewQQ,
Don't know the answer but:
In https://www.nysaves.org/home/why-ny-529-direct-plan/grandparents.html there is a note that such contributions could exceed your annual gift tax exclusion with an alternative 5-year contribution method. Perhaps TurboTax had been informed of that election and the 5 years are up? I do suggest looking at the 529 plan document for details.
