Android app - Unable to contact ADManager plus server

Android app - Unable to contact ADManager plus server

HI all, i wonder if anyone encounter the same problem. 
I can use almost all the function on the app, delete user, enable user, disable user, unlock.
It does take a while (10 secs) for the server to reflect its unlock when it says success on the app.

But when i attempt to reset password, it just says " Unable to contact ADManager Plus server"
I wonder if there is anything that I need to look into or configure?

Please assist .


                New to ADSelfService Plus?