At the adapter boundary, using the applicable response contract to distinguish request success from validated status data; test malformed replies and good-read-then-failure before the screen updates.
Also include a genuine valid status that is not favourable. The adapter should not turn every negative-looking reading into a communication failure. Preserve the distinction between unavailable data and an observed condition.
Offline cases now pass after the repair, including valid negative status and stale previous data. Supported-environment comparison remains outstanding. The training display is not released yet.