The two food-storage compartments serve different temperature purposes. Separate targets let the controls describe those purposes, but they do not reveal the entire cooling-system design.
What the observation tells you
Two buttons do not prove there are two compressors, and changing one target may not behave like disconnecting that compartment. The manual explains how the particular model manages the relationship. Guessing from the number of displays can lead to a misleading repair request.
A useful next step
Record both targets and the actual condition in each compartment. Use the documented control procedure and avoid treating one correct display as confirmation that the whole appliance is working.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.