Thanks for your reply. On a physical device, I intercepted the request for the third HLS segment and changed the response status code to 404. In that case, the request error was reported, but URLSessionTaskMetrics was missing. I also tried to simulate timeout failure scenarios: on a real device, I paused the response and did not let it continue; on the simulator, I used Link Conditioner with 100% Loss. In those cases, I did not observe the corresponding HLS request metric event. Instead, I received two error events. I will also share a link to a sample project. The screenshots are included in the Resources folder in the repository. Sample app Thank you again for your help.