Went to online check-in for LHR-LAX 281 tomorrow. On one passenger, there is a message stating "The US advises that no travel authorisation can be found for the passport details provided. Please check you have a valid ESTA or provide your US visa number".
The passenger details and passport number are correct in the booking and we have a copy of the valid ESTA, which is valid until 2024. Just called the Gold Line and was told that there is a system error which they are trying to fix and to try to check in again in a couple of hours. A bit worrying, tbh.