Android wallet error

My nephew has an “official Android Wallett”. Several month ago he has open a second account on his Android. It has a balance of 0.1201, which is seen in the algoexplorer.io. Alas, his Android now only shows the first account. And of course, he didn’t write down the passphrase for this second account.

But how is it possible, that the second account has “evaporated”??? There was no telephone change in the meantime.