Zoiper Android Client application -> Settings -> Advanced -> Supported Networks menu, uncheck "Wifi" option,only 2G/3G/4G remain checked, and the phone will fail to register with "Wrong Network Type" Error. Turns out registration will only work if all boxes are checked. Is that expected?
I have to walk frequently between different WiFi networks and, sometimes, when I walk from one network to another, the client app fails to re-register due to some registration bug. I was trying to limit my Zoiper network types to 2G/3G/4G to reduce the number of WiFi network switches and, thus, avoid different kinds of registration errors