The title says it well: the Android mobile phone will not connect to a WiFi network without an Internet connection.
Our customers can not connect to a SoftAP network created by our device. They see the SoftAP network, try to connect to it, and are immediately removed from the network.
When I connect to the same SoftAP network, a warning indicates that the said WiFi network does not have access to the Internet. I must then approve the connection to the said network. After approving it, the application we use works well.
Our customers are Austrian and we are based in Serbia. I do not know if it has anything to do with that. In addition, almost all of our Android test devices are in developer mode. Again, I do not know if it has anything to do with it, just try to give as much information as you can.