Yeah, I worked for the 2020 Census as an enumerator and we were required to put down whatever someone identified as. There were quite a few people that said to me things along the lines of “well, I think I have a Native American ancestor” and would then tell me to put down Native American in addition to white. I had people tell me clearly bullshit answers to my questions, and I had to put down whatever they claimed, those were the rules. I wouldn’t doubt if these numbers have been skewed by things like that.

Edit: also as someone who worked for the 2020 census, it would be wise to take the stats that come out of it with a grain of salt. There were a myriad of issues with counting that year, it was a nightmare.