I have a simpler problem with Availability-FS. I'm looking for details for my flight Aug 8th DEL-BOM on Air India. Under the FS method my 7am flight does not show at all. It's AI 657.

However it does show under Availability-ETR.

I thought FS was the best one for general use and ETR was the one where some flights might not show if there was no availability (although there is plenty of availability on AI 657 Aug 8th at 7am).

Confused.