I adhere to the weird behavior of Android, and I would appreciate if anyone would suggest me how to proceed.
Iv developed the application with gcm at first, now upgraded to fcm to just send messages and notifications from the server. Everything is going well using this application with a mobile connection or with Wi-Fi on an open network, but devices stop receiving notifications when they are connected to Wi-Fi behind a proxy server.
The proxy server, of course, is configured on the device, and it can work on the Internet, read email, connect to a machine with the gcm server installed; they just don’t receive notifications ... and not only for my application, but for all applications, such as parties, whatsapp and gmail ...
The Google Play service probably cannot connect to the google server ... but what can I do to force it?
I can manage all network settings, I deleted the firewall, all ports are open. If I connect to regular gateways, everything works, if I connect devices to this transparent proxy server, notifications stop coming.
Iv reads on the forums that most users use "Drony" or they are the roots of smartphones, unfortunately, these devices are in the production environment and under warranty, I can’t install a third-party application or bundle devices.
In my application, I do not directly control the proxy server configuration, this is the OS configuration, but is it normal that Android notifications do not work for the proxy?
Update:
after that, https://stackoverflow.com/a/3776261/android-query-query-files-in-javascript/232632#232632
this gives me that using the proxy server google play services are disabled -> connection failed. The TCP connection probably does not go through the proxy server. I also set up a SOCKS server, but in Android, without root, it is not possible to configure a SOCKS connection, right?