Zoom F6 Sync Problem

I only recently purchased the Zoom F6 and am having problems syncing with the Tentacle. More often than not when I plug it in to sync to the Zoom-s TC it doesn’t sync, flashing a fast red instead. In this forum I read somewhere about this same error being related to a faulty cable, but I’ve tried several now and the the problem persists, albeit intermittent. Could this be related to the Zooms TC polarity on the mini jack socket? I tried a mono mini jack cable but it didn’t work, so I’m stumped. Any help would be appreciated, or some specific Zoom F6 related instructions on syncing to the Tentacle if the problem is inherent. Thanks a ton.