Maybe debugging the Android logs can help you find the reason behind it. Please see this link from documentation about setting up android logs for debugging
https://docs.mendix.com/howto/mobile/native-debug#4-1-using-android-logcat
We resolved the issue and just posting the solution as it may help someone.
The issue was the certification is incomplete for the server and Android was not able to connect to the server. Android logs from Mendix app were not helpful as it was not giving any proper error message. And we have tried different debugging ways suggested in Mendix documentation and support team.
We user Profiler from Android Studio to check the connections and understood that the connection is not getting established with the server. As the Mendix Andorid application is not giving any errors in the logs we could not proceed further
So, we have created a sample Android application with Android Studio and tried connecting to the server which gave the right error message as
javax.net.ssl.SSLHandshakeException: java.security.cert.CertPathValidatorException: Trust anchor for certification path not found.
Post this it was pretty easy to fix the issue in the certification path from the server side.