Testng suites are not executing parallel on android device/simulator

Steps :

Created to testng suites with different ‘port’ of appium as parameter

As testng doesn’t run parallel on suite level, so used maven-surefire-plugin
plugin details in pom.xml is mentioned in below gist url.

ran 2 instances of appium server on 4723 and 4725 ports

executing mvn clean test

Excepted : Both the testng suite run parallely on device/emulator.

Actual : Initial command is running on both devices/emulator but after some time client request is going to different instance/port.

please help.
appium log and testng xmls gist are mentioned below.

Environment

Appium version : 1.7.1
Desktop OS/version used to run Appium: macOS Sierra version 10.12.5
Mobile platform/version under test: Android 6.0
Real device or emulator/simulator: Both
Appium CLI or Appium.app|exe: CLI
Link to Appium logs and testng xml