Wifi java.net.SocketTimeoutException: failed to connect to host

[SergeyBukarev]

Preconditions:

1. Network hadware:
   Amplifier of 3G/LTE signal + Wifi router.
2. Devices:
   Samsung galaxy A10 Android 9
   iPhone 8 Plus iOS 12.4
3. Application:
   I have two applications (iOS and Android) that interact with the same server.
   Android aplication uses library okhttp:4.2.0 and makes requests through okhttp.

Test #1
Device: iPhone 8 Plus iOS 12.4.
Mobile network (3G/LTE) data is disabled, connected by wifi.
Request GET with MyTestApp iOS aplication:
The request is successful and the result is returned.

Test #2
Device: iPhone 8 Plus iOS 12.4.
Mobile network (3G/LTE) data is enabled. Wifi is disabled.
Request GET with MyTestApp iOS aplication:
The request is successful and the result is returned.

Test #3
Device: Samsung galaxy A10 Android 9
Mobile network (3G/LTE) data is disabled, connected by wifi.
Request GET with MyTestApp android aplication:
Logcat: HTTP FAILED: java.net.SocketTimeoutException: failed to connect to [MyServerName]/46.148.196.218 (port 4002) from /10.0.1.7 (port 37470) after 30000ms

Test #4
Device: Samsung galaxy A10 Android 9
Mobile network (3G/LTE) data is disabled, connected by wifi.
Request GET with RestApiClient android aplication:
(https://play.google.com/store/apps/details?id=com.app.restclient)
Logcat: HTTP FAILED: java.net.SocketTimeoutException: failed to connect to [MyServerName]/46.148.196.218 (port 4002) from /10.0.1.7 (port 37504) after 60000ms

Test #5
Device: Samsung galaxy A10 Android 9
Mobile network (3G/LTE) data is enabled. Wifi is disabled.
Request with MyTestApp android aplication:
The request is successful and the result is returned.

Conclusion:
The ios application always work fine with any network configuration. Android application does not work through a wifi router in 80% of cases.

[yschimke]

You should discuss this on stackoverflow. There isn't anything actionable for us to investigate as we don't have a bug reproduction here.