Why can smart glasses pair with a phone while a feature fails?
Pairing is only one step. The app may still need permissions, a supported protocol, account access or an internet connection to complete the feature. A paired device is not proof that the full workflow is ready.
Test the smallest operation at each stage
Establish the local app connection first, then a simple display or input action, then the service-dependent task. The first failing stage narrows the problem. Repeating the entire workflow without that separation often produces the same vague failure.
If a local text card works but a calendar cue does not, investigate the account and service route. If neither card reaches the display, examine the app/device interface. Pairing status remains useful evidence, but it should not be asked to prove parts of the system it does not cover.