Understanding fare class availability
I'm checking availability on the routing KNO-CGK-LHR on GA on 17th April.
The KNO-CGK leg shows L9 (L is the cheapest class) H9 S9, etc., but CGK-LHR shows L0 H0 with S9 the cheapest class.
However, if I check the flights separately, both KNO-CGK and CGK-LHR have L9.
Is there a particular reason why this would be?