This is related to Twitch API Bugged...? but I’ve since narrowed down the error and the other thread seems to have gone stale.
The /streams/ and /stream/ endpoint is sometimes responding with a user object on the channel property. Seems to happen randomly but it seems to be happening often enough that I can reproduce it every few minutes.
I ran some numbers and over the past day, 0.94% (sample size of 192,209) of the stream objects I pulled showed this issue. Hopefully this helps, please let me know if there is anything I can do to help.