This is not something I have observed myself, but whenever I did use this (or the streams end point) I only ever counted a stream as offline if it was not in the response for three concurrent calls where I called the end point via cron once per minute.
So it smoothed out any bouncing that occurred. Whether that was the streamer bouncing or TwitchAPI, I smoothed
These days I’m on webhooks instead
https://dev.twitch.tv/docs/api/webhooks-guide/
Depending on your use case for this endpoint, this might be a better solution