Seems to be a 5.1.1 issue, found similar post on the web with people testing different app lock programs.
The solution is to enable a feature which isn't added to avast yet.
In settings -> Security -> "Apps with usage access" and then enable the app lock program. Avast is not listed there yet.
Guess we have to wait for an update from avast.
Sadly, I purchased their Mobile App. I just had the worst customer experience while trying to get the issue of enabling usage access for Avast on Lollipop (Android 6.0) with a rooted Samsung Galaxy Note 5. You'd think they have US support and someone who can understand enough English to respond to understanding what the issue that one is attempting to explain.
Avast is not listed in the Apps with Usage Access list on the mobile device. Even after giving Avast full permissions via the App drawer App locking on the Avast app still does not work. It's now 2017 and the Avast Mobile App seems is still not updated to work properly.
Has anyone had any luck in resolving this issue this year (2017) or found a workaround?
Also, does anyone know how to get a refund?
Thanks in advance!