It distinguishes an immediate unresolved symptom from a later change. That history supports assessment without proving a replacement part failed.
What the observation means
Record which functions worked, for how long and what preceded the new event. A different cavity or mode may now be involved.
A useful next step
Provide the earlier report and current observations together. Stop use for dangerous symptoms and avoid repeated tests to establish a precise failure time. Let the provider review any warranty or follow-up process before assuming another component must be purchased.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.