Discussing the repro with MCPE-151334, it isn't completely the same. In my case, the child account is the primary and only account on the Android device. But it has similar issue to both this bug and MCPE-37685 in that the server list is not persisted for a restricted child account.
I'm not sure this is a complete duplicate. In my case, the child account is the primary (and only) account on the Android device. But the symptom is the same.
Discussing the repro with MCPE-151334, it isn't completely the same. In my case, the child account is the primary and only account on the Android device. But it has similar issue to both this bug and MCPE-37685 in that the server list is not persisted for a restricted child account.