I am using Avast free 18.7.2354 with Windows 7 64bit. Periodically Behavior Shield turns itself off. I do not see a pattern. This has been talked about since 2017 version 17, with promises of a fix in the new version. Version 18 still not working right. Other posts mention it turns off after a boot, in my case that is not the case and happens at random.
Have you run avast repair?
Yes, this seems to be a “flaw” in the program design or else there are applications that are able to influence the Avast Software settings of a user external to user authorized control.
A partial log from my records for Avast includes:
[i]07/06/2018 01:08 PM - Another Avast alert instance. Behavior Shield turned off again and need to re-start - again.
10/05/2018 09:14 AM - Avast alert that Behavior Shield is off. None had been turned off by my actions.
Protection: Core Shields
ON:
File Shield
Web Shield
Mail Shield
OFF:
Behavior Shield
10/05/2018 09:15 AM - Behavior Shield turned on again.
10/05/2018 12:01 PM - Avast alert that Behavior Shield is off. None had been turned off by my actions. Behavior Shield turned on again.
10/22/2018 03:16 PM - Upgraded Avast Antivirus and on re-start find that Behavior Shield has again been turned off. Behavior Shield turned on again.
10/29/2018 11:57 AM - Avast alert that Behavior Shield is off. None had been turned off by my actions. Behavior Shield turned on again.
[/i]
Behavior has been prevalent for some time now, across updates to program.
HTH
If Repair doesn’t fix the problem, try the following:
Clean Install of Avast:
https://goo.gl/4Ptzkf
If you need additional help with the Clean Install, watch this:
https://youtu.be/p-h3myRD51A