behaviour shield is turning off automatically

behaviour shield is turning off automatically often in my pc and I need to turn on it manually most of the time

  • Which version of Windows?
  • Which version of Avast(Free or IS or premier)…?
  • Other security related software installed…?
  • Which AV(s) did you use before Avast…?

Repair & Clean Install of Avast https://goo.gl/t7aJGq
Repair Avast:
Open the Avast User Interface > Menu > Settings > Troubleshooting > Repair App. > Restart the Computer or,
Control Panel> Program and Features (Add/remove program)>Select Avast> Select Repair. Reboot when completed
https://www.avast.com/faq.php?article=AVKB204

If Repair doesn’t fix the problem, try the following:
If your Avast settings are not the default settings and you want them restored after the Clean Install, follow this before removing Avast.
https://goo.gl/TXjM7h
Clean Install of Avast:
https://goo.gl/4Ptzkf
If you need additional help with the Clean Install, watch this:
https://youtu.be/p-h3myRD51A