iPhone simulator cannot get access to https backend

Hello! My application works fine on Android device communicated with https://backend. I try to run my application on iPhone simulator on my mac mini machine but the communication with https://backend does not work. The difference is that the first request from Android is POST:

xxx.xxx.xxx.xxx - demo [31/Jan/2018:14:11:39 +0300] "0.013" - - - 200 200 "POST //login HTTP/1.1" 38 - "Mozilla/5.0 (Linux; Android 4.4.2; T1-701u Build/HuaweiMediaPad) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.143 Crosswalk/23.53.589.4 Safari/537.36"

but from iPhone simulator is OPTIONS:

xxx.xxx.xxx.xxx  - - [31/Jan/2018:13:59:10 +0300] "0.002" - - - 200 200 "OPTIONS //login HTTP/1.1" 13 - "Mozilla/5.0 (iPhone; CPU iPhone OS 11_2 like Mac OS X) AppleWebKit/604.4.7 (KHTML, like Gecko) Mobile/15C107"

and after that communication on iPhone simulator stopped.

What is wrong?

Thanks in advance!

BR,
Anatoly Shirokov

Did you try debug?

Yes, I got on client the following response:

console.log:
            {"_body":{"isTrusted":true},"status":0,"ok":false,"statusText":"","headers":{},"type":3,"url":null}