Usually the function needs to be identified separately: a control lock may only prevent settings changing. Do not assume it locks the door or provides child protection.
What the observation tells you
Some chest freezers have a physical key lock, which is a different mechanism with different use instructions. Confusing the two can leave access unsecured or lead to forcing a door that is actually locked. The icon alone is insufficient.
A useful next step
Read the exact feature description and use appropriate supervision and access precautions. If a physical lock or latch is faulty, report it as such rather than changing electronic settings.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.