Is there a meaningful difference in how detectors handle first-person vs third-person writing?

testing something in my classroom and want to compare with others

i’ve been having students run the same content in different POVs through detectors as an exercise. first-person reflective essays and third-person analytical essays on the same topic. the first-person versions consistently score lower for AI probability.

my interpretation: first-person writing is harder for AI to imitate convincingly because it requires specific autobiographical details. or alternatively, detectors are trained on more AI-generated third-person content. is either of those explanations right?