PAI Up can only have one wallet active at a time. If you choose to start a new wallet or restore an existing wallet, the currently active wallet must be erased first.
If you erase your wallet without writing down its Paper Key, your value will be lost. To prevent this, you must first enter your Paper Key for the currently active wallet to make sure you have it written down correctly. The wallet will then be erased, and you can create a new wallet or restore a previous wallet.