The cabinet may not yet have reached the intended frozen-storage condition. Some models indicate that startup state with a warning, but its exact meaning must be checked.
What the observation tells you
An alarm at startup is not permission to load vulnerable food immediately, nor proof that every later alarm is harmless. The selected target is different from the achieved condition. Keep the door closed during the documented cooling process.
A useful next step
Follow the model's startup and acknowledgement instructions. If the freezer does not reach the expected condition or shows another warning, seek advice before relying on it for storage.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.