Locate not working

App is set to auto update, so is on latest version. Device is a Sony Xperia M Black, again with auto update for OS. This used to be a great feature of Avast, but has been getting less and less reliable - come on folks, what’s the problem?
It works intermittently, but not enough that I can trust it

Recently my device, a ZTE Z812 was stolen but I didn’t worry or stress about it since I have Anti-Theft installed. I logged on to the Avast web site to locate my phone and I was hit in the face with my WORST FEAR… the message kept coming back the same over and over " WE CANNOT CONNECT TO YOUR DEVICE " My phone is gone and the Avast software did not protect me or give me the peace of mind that they promised. I still have not heard back from the SUPPORT CENTER re:- A ticket I submitted.

https://www.avast.com/faq.php?article=AVKB116#artTitle (Lost/Stolen phone)