I'm running into an issue trying to build a stopover:

BKK-(KIX)-LAX in business. Using a one way BKK-LAX search I'm able to find several scattered dates connecting in KIX. However, when trying to replicate those exact same dates/flights in Multi-City they aren't showing up in the search. Searching BKK-KIX or KIX-LAX one way individually on some of those dates doesn't work either. Is this a married segment that can't be broken up with a stopover? Or some other rule?

Edit: I should have RTFM.. likely married segment restriction?