How far can Alabama go back and adjust my taxes for mistakenly claiming the rural physician tax credit for more than five consecutive years?

I claimed the rural physician tax credit for 2006-2016 but I am only allowed to claim it for 5 consecutive years. Now the state has disallowed the credit and sent me a bill for 2011-2016. Wouldn’t the statute of limitations come into play? My understanding of the tax law was that they could only go back 3 years unless I failed to file a return or omitted more than 25% of my income.