Comparable timing helps show whether the compartments change together or independently. Readings separated by a shopping load or control change can suggest a false relationship.
What the observation tells you
The instruments still need suitable ranges and placement. A fridge thermometer may not be appropriate for the freezer, and neither target display necessarily gives a current measurement. Avoid holding both doors open while trying to watch the readings.
A useful next step
Record conditions briefly, keep the measurement method consistent and note recent events. This provides a clearer pattern for assessment while food safety remains the first priority.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.