I have read sections 6.5.4. Contextual reference validity and 12.3. Application shutdown lifecycle again. If you stop an app, all contexts must be destroyed, i.e. all contextual instances must be destroyed.

For pseudo-scopes the behavior is undefined, but the reference is invalid from CDI spec POV and the application should not invoke a method of such a reference.

For normal scopes (and client proxies) the only requirement is: "the context associated with the normal scope is active". On the other hand, it seems logical that a proxy is bound to the "container" which has been stopped and none of associated contexts is active any more.