Don't worry too much about it. I guarantee her "burnout" is due to waking up right before the streams and not going to sleep earlier. Its not the kind of burnout that you feel when you don't like doing something, which is worse.
If you don't give yourself enough time to relax before streams and get enough sleep, your brain will "tag" it as something unpleasant since you feel letargic and it'll feel like a chore until you fix your routine.
Non-treated allergies can also affect your mood and energy levels even if you don't feel any physical effect. I know Ame is a contrarian and she's kind of a mess but I also know how much she loves being in Hololive, so I trust her to get out of this, even if we need to remind her.