Today I tried to use an https proxy, it has no effect.
I did some research, installed Wireshark and tried to catch some requests. Of course, without MITM I can't read the packets, but I can check if the application is trying to send them. And yes, it happened! Moreover, he gets some answers. At the same time, I checked the main problems with SSL; the browser opened the activation URL correctly, without errors.
I think the error is somewhere near (or inside) the "no_internet_connection" exception, something like: "i got wrong answer from server / i can't read it / or something well throw exception" and the closest exception is "no_internet_connection"