The timing is really strict when it's not a counter hit, you barely have time to do a 2C~623AA > Falling 2c. On counters it's much easier.
Practice it with counter-hits turned on until you have the timing down. If they're teching before jC hits, you're hitting it too late, if they're teching after jC but before 2C, you're doing the jC too early. All about practice. Also make sure the jump is a jump forward, (9) which I'm sure you're doing, but it's still worth it to be said.
My inputs go 623A 9A C 2 C 9 2 C. If you split up the motions and the inputs, you can time it easier (as in, don't go from neutral to 2C when you land, put the 2 in during the jC). Basic stuff, and if you're doing that already, then just practice
