Had an issue with IP configuration, where Pico didn't get a new IP after configuring wifi settings in the portal. After connecting to newly configured network, the IP was still the same as in AP mode (192.168.42.1). I think the same problem is described here:

https://stackoverflow.com/questions/40069654/how-to-clear-static-ip-configuration-and-start-dhcp

And a solution is to change WiFiManager.cpp line 196 to
WiFi.disconnect(true);

And add after that:

delay(500);
WiFi.config(INADDR_NONE);