Chaturbate has a very broad interpretation of the laws against "portraying an underage person" in the context of pornography. There is no question that it is illegal to do that in the US, but it seems most producers/networks interpret this exclusively to mean instances of a performer/character claiming to be underage. Some go the next step to warn or ban anyone acting/dressing/styling in a way that would be associated with being underage (pigtails, lollipops, schoolgirl outfits, etc). Chaturbate is unusual in that they seem to feel that a 24 year old dressing, styling, and acting like a 24 year old can be considered to be portraying an underage person if their facial structure and complexion are unusually youthful.
They're also remarkably inconsistent in enforcement, with blatant ageplay accounts being allowed to broadcast for months sometimes and no age checks at all for "exhibitionists".
If you want to keep trying with Chaturbate, your best odds may be wearing way more makeup than you usually do, and aiming for a look that seems "sophisticated" rather than "youthful". Otherwise, there are plenty of other sites out there that are more about warning, communicating, and achieving compliance rather than ban and ignore.