Yes, you'll need to use 6A instead. What you've seen was probably a combo off a crouching hit 5B starter, which has much better proration than 6B.
5C 6A or 2C 6A work on some characters, but when in doubt, 6A!
Blue beating? Shouldn't be happening, the proration is more than enough to not allow air tech. Or maybe you didn't turn on Emergency Teching and the dummy is most likely hitting the ground before 6D hits.
Delay Gauntlet Hades follow up as much as you can and do 6D as soon Ragna lands.