I feel like this makes some sort of sense. You're saying "no underwear" I guess?
The engine isn't infallible, no engine is. It guesses based on various heuristics whether something is nsfw, and goes with that. Sometimes sfw stuff is marked as nsfw, something nsfw stuff is marked as sfw. Maybe this will improve if the engine changes, but for now it's about par for the course.
Maybe there's some change that can be made in these areas, but just my guess is there's not a lot they can do about it.
I mean for example "prompt":"cat","negativePrompt":"underwear","maybeNsfw":true - but it's just a cat, and it doesn't matter what you type in the prompt, response maybeNsfw will always be true. I can use in negativePrompt other hard word and maybeNsfw work correctly, but underwear is a trigger word.
Yes, I only hope that the situation will improve in the future. But now some NSFW content (very explicit) is still allowed through without marking.