I came across this when I was trying to make a double-NOR-style JK Flip Flops and couldn't get it to work. I pivoted to a OR-NOT-AND-style JK Flip Flop do, but it didn't work until I used a Master-Slave JK Flip Flop instead of a bare JK Flip-Flop because of the race condition.
Here's my MSJK flip-flop if you want to try that.