Using Avast Free 19.5.2378 (build 19.5.4444.500) on Win10 Pro for several years. After the last two Avast updates Avast starts up with the 4 core shields turned OFF. Doesn’t seem right to me. They were on before the update.
Suggestions?
– Larry
Reboot a couple more times, see if it helps
I’ve seen this on my installations at times however a few reboots and all was resolved for me. 
If that doesn’t work,
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
This seems to have rectified itself with various updates of Avast.
@ larrymcg,
Sometimes using the gui update and downloading your update via the online Update button will result in glitches in internet connection and affect how the online install works out.
I suggest downloading and saving a copy of the full offline installation file from here: https://forum.avast.com/index.php?topic=227342.0
You can always run the full installation file on top of the avast program already in place (Install-over-the-top). There are fewer issues when done this way.