Is Asiana's *A search engine (https://flyasiana.com/I/KR/EN/Redemp...egistTravel.do) any good or am I wasting my time?

I am trying to find business class award space on the route KUL-FRA.
I searched many dates, including dates 6+ months into the future. All I can find is space in economy.

If I use the UA search engine for comparison, I get plenty of choices. Here is a concrete example:
Searching *A awards KUL to FRA on 23 May 2023, UA's search engine shows the following business class awards are available:
KUL-BKK-FRA on TG
KUL-BKK-CPH-FRA on TG, SK
KUL-BKK-IST-FRA on TG, TK
KUL-BKK-DEL-FRA on TG, AI
KUL-SIN-BKK-FRA on SQ,TG

For the same date, Asiana search engine shows me a few TK and SQ economy awards only (even though I searched all classes).

So what's up with that? Can I book the awards that show up on United if I call the Asiana hotline?
Also, how to find and book EY awards using Asiana miles? Thanks.