`WiFiInterface::connect (...)` problem on inexistent open network with `UDPSocket:sendto(...)`

[giorgiogallina]

I am working on an Arduino GIGA, which is running MbedOS. I have already reported the issue for the Arduino's library, but I suppose there is a deeper problem.
The related issues are: arduino/ArduinoCore-mbed#1080 and arduino/ArduinoCore-mbed#1045

When a connection to an open WiFi network fails (SSID not found) -- hence invoking function WiFiInterface::connect (...), -- then if I open an Access Point and try to communicate with the user that connects to it, this fails too on UDP communication at UDPSocket:sendto(...), returning error NSAPI_ERROR_PARAMETER.
DHCP is being used.

No issue arises on protected WiFi networks (same scenario in all the rest).

I know I have given too few details, but since I am working through Arduino and not directly on MbedOS, I an not really into the project.

Thank you