Visible SMS

I own two Samsung J5.
On both of them I installed Avast Anti-Theft.
The phones are mutually “friends”.
I am able to sent a SMS commands from one phone to the other (and the commands work fine), but the SMSs are visible in the destination phone.
Actually I selected the “support for Android 4.4” option.
What have I to do to hide the SMS commands?
Thank you.

Hello, I am not sure this feature works on Android 5.1 because of changes, made by Google later on. It worked on older Androids only.

If you prefer AMS4, revert back.