This is a misinterpretation of the 14th amendment. It's precise wording is: All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside....
That subject to the jurisdiction thereof was not put in there without thought. It leaves room for a degree of interpretation. But for Indians residing on sovereign independent reservations there's no ambiguity whatsoever - they are excluded and there remains a supreme court ruling on the books upholding this. However, congress can choose to grant citizenship to whomever they choose and indeed a special exception was carved out for natives in the early 20th century - The Indian Citizenship Act. [1]
That subject to the jurisdiction thereof was not put in there without thought. It leaves room for a degree of interpretation. But for Indians residing on sovereign independent reservations there's no ambiguity whatsoever - they are excluded and there remains a supreme court ruling on the books upholding this. However, congress can choose to grant citizenship to whomever they choose and indeed a special exception was carved out for natives in the early 20th century - The Indian Citizenship Act. [1]
[1] - https://en.wikipedia.org/wiki/Indian_Citizenship_Act