Is Potemkin Buster 5f or 6f? Video Proof
Answer: 5f up close, 6f with Just The Tip!
Giovanna's 5H is -5 on block, which gives her the ability to jump on the same frame as a blocked hit when outside of the PB's 5f range, but inside the PB's 6f range.
You can also see this with the "Punish" status in the top right - Punish appears when you hit an enemy during the recovery frames, and the PB hits on the last frame of the 5H recovery from Gio when in 5f range, but not in 6f range.