Connecttimeout not honored

We are experiencing issues with the OkHTTP connect timeout not being honored on a Pixel 3 device on Android 9. We set it to 10 seconds in the builder, and when using that OkHTTP client and enabling AirPlane Mode, the request we issue will just hang forever.

private static OkHttpClient client = new OkHttpClient.Builder().connectTimeout(10, TimeUnit.SECONDS).build();
[..]
Response response = client.newCall(request).execute();
//Should continue here after 10s, but keeps hanging at this point.
if (response.body() != null) {
//do something
}

The weird thing is, it works ok with other devices, also on Android 9, and the emulator. The issue happens when in AirPlane mode, but also when just having no mobile network in a building.

I tried testing the app with OkHTTP 4.0.1, 3.14.2, 3.12.1 and 3.4.1, all exhibit the same issue.

[peterdk]

It might be related to a VPN service we use, we discovered. But still, it’s weird that the connection timeout is not enforced always somehow.

[peterdk]

Ah ok, I understand now. OkHTTP connects to the VPN socket, to the connect timeout is not triggered. But the VPN internally just doesn’t give a proper error, until after 5 minutes or so. That’s indeed then not a OkHTTP issue.