I would suggest the following:
1. Delete the old app and Bridge from your test device.
2. It's quick and easy - create a new set of certificates from Apple and download them to your keystore.
3. Reboot your device (Phone - not PC)
4. Re-create the B4i Bridge and install it on your device
5. In your IDE --> Tools --> Build Server --> Server Setting --> Choose 64bit
4. Re-compile your app and test on your device
That should do the trick !! (If it doesn't - throw the device in the Dustbin and revert to Android !!
)