I tried to run the following search twice and every day errored out both times.

There were errors. If you search again within the time specified by the "max cache age" option, it will retry only the failures, and fill in the missing data.
Searching ORD-NOS on 2023-08-17 --> Error searching (Unknown error)
Searching YYZ-NOS on 2023-08-17 --> Error searching (Unknown error)
Searching ATL-NOS on 2023-08-17 --> Error searching (Unknown error)
Searching IAD-NOS on 2023-08-17 --> Error searching (Unknown error)
Searching NYC-NOS on 2023-08-17 --> Error searching (Unknown error)
Searching LAX-NOS on 2023-08-17 --> Error searching (403)
Searching ORD-NOS on 2023-08-18 --> Error searching (Unknown error)
Searching YYZ-NOS on 2023-08-18 --> Error searching (403)
Searching ATL-NOS on 2023-08-18 --> Error searching (Unknown error)
Searching IAD-NOS on 2023-08-18 --> Error searching (403)
Searching NYC-NOS on 2023-08-18 --> Error searching (Unknown error)
Searching LAX-NOS on 2023-08-18 --> Error searching (Unknown error)
Done searching