SMS messages not being monitored on one kid's phone, but fine on the other kid's phone

My teenagers have identical LG Android phones.  NF monitors SMS messages fine on my son's phone, but I cannot get it to do so on my daughter's phone. 

 

It is set up in security settings to be an administrator on the phone.  I've also uninstalled and re-installed the software.  Any ideas on what's wrong? Anything else I can check?