Any advice greatly appreciate.

I only done either a round trip/ one way ticket redeeming CX award tuckets. This year I was able to redeem 3 J from JFK - HKG in April. I'm planning for a trip next year that would include a Stopover? In TYO?

From reading online, I think CX allows stopovers, on round trip tickets but not one ways. I assume the error with my plan below is because it's not a round trip per se?

Example below which I found availability for Y
JFK - TYO thru JAL October 18 in Y
TYO - HKG thru CX October 20 in Y

However, every time I try to select the second portion TYO-HKG the system generates an error msg saying too many stopover/openjaws.

Just wondering where I went wrong.

Thanks