Some models include a time-based safety limit. The permitted duration may depend on the selected level and must be checked in the manual.
What the observation means
A timed protective stop is different from tripping the electrical supply or displaying a component fault. Long simmering still requires appropriate supervision.
A useful next step
Record the level, duration and message. Use the documented procedure rather than repeatedly overriding a limit. If shutdown occurs far outside the described behaviour, request assessment. Do not disable safety features or assume a continuous low setting is intended to operate indefinitely.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.