What do you mean by syncing your iPhone? Are you trying to use Audio Timecode with Apps like FilmicPro or MovieSlate? Or do you try to connect your Tentacle to the setup app?
I am asking, because these are two different things and you need to use different cables:
- For feeding timecode into your iPhone you need a special “Tentacle to iPhone Cable” here: https://shop.tentaclesync.com/product/tentacle-to-iphone-adapter-cable/
- If you want to use the Tentacle Setup App, you need the white 4pin TRRS Cable which comes with the Tentacle.