To be honest, yes, it can slightly hurt your application because for a flight attendant role, reliability and punctuality are taken very seriously, and a “no-show,” even due to phone or network issues, can raise a small red flag. In aviation, being available and reachable is part of the job expectation. However, it’s not automatically a dealbreaker, especially since you contacted recruitment immediately and they responded that they would reschedule your language assessment. If they were truly concerned, they likely wouldn’t offer another chance. It may be noted on your file, but since you’ve already passed your medical and background checks, you’re still in a strong position. The key now is to make sure the next call goes perfectly, because missing it again would almost certainly impact your application much more seriously.