SocketWrapper library: MbedClient.connected() returns false even data are still available to read.

The Client connected() method is documented as

Whether or not the client is connected. Note that a client is considered connected if the connection has been closed but there is still unread data.

from https://www.arduino.cc/reference/en/libraries/ethernet/client.connected/
or https://www.arduino.cc/reference/en/libraries/wifi/client.connected/