If I had to guess why you were accused of being ChatGPT, its probably because of your tendency to write longer form answers which tends to be the style ChatGPT uses.
This is when, on Reddit, you'd see a bottomless thread of the very first joke that comes to mind, posting an obvious GPT output. Then, reply after reply with the exact same premise. Maybe a link to a sub called UnexpectedChatGPT, which is a place that curates screenshots of entirely predictable GPT responses.