iOS does not normally interfere with the calling features of third-party apps, nor does it have any built-in automation specifically designed to detect and resolve issues with those apps.
Third-party app developers are responsible for developing, maintaining, and troubleshooting their apps' calling functionality. While iOS provides the operating environment and necessary system-level frameworks, it does not automatically diagnose or fix bugs within individual third-party apps.
Although certain iOS settings, permissions, background activity restrictions, or system-level features may affect how an app functions, it would be incorrect to automatically attribute every issue with a third-party app's calling features to iOS. The root cause must be investigated to determine whether the problem lies with the app, its configuration, its servers, network connectivity, or an interaction with an iOS feature.