Hey, this is a known issue. During peak hours, Auto mode can hit capacity limits on the model it tries to route to.
Workaround: manually select a specific model, for example composer-1.5, instead of Auto. This usually fixes it because it avoids the overloaded model. A few other users confirmed this helps: Repeated High Load Error
The team is aware of the Auto mode routing behavior during high demand.
Let me know if switching models helps.