On the BitBox01 a hidden wallet always has 2FA enabled. If you go to "Manage Device" in the hidden wallet and it shows that 2FA is enabled but the BitBox01 is not paired, you cannot make transactions until you have re-paired your BitBox01.
Before proceeding, please ensure that you have moved all coins apart from the ones in the hidden wallet off the BitBox01. Also ensure that you have your microSD card wallet backup and know your wallet recovery password.
To re-pair your BitBox01 follow these steps:
1. Install the "BitBox 2FA" app from the app store on your phone.
2. Unlock your BitBox01 standard wallet, not the hidden wallet.
3. Go to "Manage Device" and start the pairing process. Follow the instructions to pair your BitBox01 to your phone. Pay attention to the BitBox 2FA app as some instructions are displayed there and they might be hard to read.
4. Once you have successfully paired your BitBox01, do NOT enable 2FA. The standard wallet should now show that the BitBox01 is paired but 2FA is disabled.
5. Unplug the Bitbox01, replug it and unlock your hidden wallet.
6. Go to "Manage Device". Here it will say that the BitBox01 is paired and 2FA is enabled (good).
7. Now make a transaction out of your hidden wallet, confirm the transaction in the mobile BitBox 2FA app and then confirm it on your BitBox01.