As we see in the latest chapter, Orochi seemingly orchestrated an incident on the night before the Fire Festival at Port Tokage, which caused the allies of the Nine Red Scabbards not to appear at the promised port.
As many are theorizing, there is a traitor among the Red Scabbards.
We also know that the traitor allowed Jack to find Zou twice. Inuarashi thought he was being told how to find Zou specifically, but it could also be that he was simply given a Vivre Card for Raizou, and hence was certain that the Minks were hiding him. How would he have got it, though?
Well, Kikunojo was specifically left behind in Wano to gather intel, it’d have been logical to give her some Vivre Card so they could meet up later. They resurfaced in Kuri, as soon as she separated from them she ran to the leader of Kuri, Jack, and gave him the Vivre Card so he could stop them dead in their tracks. It’s why they were spotted as soon as they took to seas, and how they were able to sneak back unnoticed (Kiku mentions that she was unaware they had returned).
But, why Kiku?
Wasn’t she part of the Red Scabbards? Well, not initially. She looks much younger than Kin’emon and co, and Oda all but confirmed in the last SBS that she was not the person seen in the group on Yasuie’s flashback. Meaning, she was not an original Scabbard. Oda also said that “this discrepancy would be explained in due time”. Meaning, there’s a secret to it.
My take is that the original 9th Scabbard (be it Izo or someone else) left, and Kiku replaced them as a spy from Kaido. She even wears a horned mask, the mark of the Beast Pirates!
We know Kaido is not above such schemes (having put Apoo as a spy in Kid’s alliance), he probably thought he needed such an upper hand against a former Roger’s crew member (and given that Oden gave him his only scar, I’d say he was right).
*Theory by Swani
