People in Petaling Jaya say “KL” and mean the airport they last used, which is often KLIA. Operators who grew up on turboprops still default origin to Subang because the code is honest for a few morning banks.
On a Penang Friday search, an SZB default can show two flights and a grey afternoon. The same day from KUL is a full grid. The searcher does not open the origin picker. They assume Penang is thin that week.
A destination search study we wrote last year spent four pages on this one default. The operator changed it to KUL and kept SZB in the picker. They did not need a new calendar. They needed the first screen to guess the airport the way a weekend booker guesses it.
If your origin field uses GPS, test it from a desk in Damansara, not from the airport road. GPS near the office can still prefer SZB. The booker is not on the airport road yet. They are on the sofa.