Ah this happens again... I think the reason is that the cabins data we bought is not reliable and it says flights on this route has only biz class... I'm seriously considering not using cabins to filter flights until we found some better source...
Same issue here:
2015: 116K bkd | 1.6M brnd | F: OZ,NH,AA,EK | J: UA,CA,TK,DL,TN,AF,VA | LIH,NRT,ROR,PEK,CNS,BOB,MEL,TLV & Pacific Hopper