After trying it in the lab, it does seem like the problem is in doing 623C too soon. I landed it on Izanami, then tried replaying the combo on the other characters, and most of them ended up being slightly out of reach. Apparently I'm not doing Snaphance at the dash's max distance, which means I'm not delaying it enough. Maybe it's the same for you?
For the record, the other characters it did land on are Nine, Hibiki, Relius, Tsubaki and Kagura. Jin is not even listed as the viable target for the combo on the JP Evernote.
I didn't know there was a viability list. Ill just check that out. Maybe thats my issue as well.
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