If this is the case, you should use an OSC connection:
- Make sure your iPhone and laptop are on the same network (either ad-hoc or through a router, ad-hoc recommended).
- Start the Griid Connector on your laptop
- Make sure the Control Surface in Ableton Live is set to Griid, with input/output also set to Griid.
- Start the Griid app on your iPhone, tap OSC Connect. Your computer's IP should appear underneath Automatic Discovery. Select it and it should turn blue.
- Tap Go to launch your Live set.