Freezing storage requires more than being just below the point where water starts to freeze. Official domestic guidance recommends a freezer around minus eighteen degrees Celsius.
What the observation tells you
A small ice cube remaining solid does not demonstrate that the whole food load is stored at the intended condition. Different foods have different textures and freezing behaviour, so squeezing one pack is not an accurate thermometer. The display may also be a target rather than a current reading.
A useful next step
Use the model's recommended setting and appropriate monitoring. If performance is uncertain, protect the food and investigate the actual storage conditions rather than relying on the presence of some ice.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.