Cathay Pacific Asia Miles - KA vs CX online booking engines

I am booking a return ticket HKG-HKT in biz (online from far away). For the same dates/flight KA gives me a D fare and CX a much more expensive J fare. I have tried at different times or simultaneously. Is that common? Will it make a difference regarding miles/TierPoints credit on my BA exec club account (I am not asia miles/MPC)?

What dates are you looking at? I'm getting the same fare on both websites...

On CX.com:
01 Jul CX6716 Dragonair HKG 14:40 HKT 17:05 0 3:25 320 eTicket Business Standard (D)
06 Jul CX6717 Dragonair HKT 18:05 HKG 22:50 0 3:45 320 eTicket Business Standard (D)

HKD 5,956.00 Adult x 1 HKD 5,570.00 HKD 386.00
Total fare HKD 5,956.00


On KA.com:

01 Jul KA212 HKG 14:40 HKT 17:05 0 3:25 321 eTicket Business Standard (D)
06 Jul KA213 HKT 18:05 HKG 22:50 0 3:45 321 eTicket Business Standard (D)

HKD 5,956.00 Adult x 1 HKD 5,570.00 HKD 386.00
Total fare HKD 5,956.00

Thaks for taking time. This is for Xmas period with departure Dec 21 to 23. it was 5570 KA or 12000+ CX. I booked on KA anyway. So that might have changed availability. When booking I opened the two windows at the same time. But I checkedf several times over the past couple of days, so it was a systematic difference.