@mnswiftone,
Why didn't you simply go back to the previous build It is one of the options.
I'm back on build 14936 and have changed my Insider update preference to slow.
That is not necessarily an option if you need a fix/feature in the later builds of Windows. I actually opted for fast ring builds after the antivirus issue was introduced, because they added features in WSL (Windows Subsystem for Linux) which I needed for work. In fact I uninstalled Avast as I was opting for the Windows Preview Program Fast Ring builds. My alternate was dealing with a virtual Ubuntu session with limited system resources or working over VNC with a 2nd computer and dealing with its related restrictions and limits and extra costs.
So for the time being, goodbye Avast, I need my computer to do what I need it to do so I can pay rent.
If Avast employees haven't done so yet, they should reach out to Microsoft to find out if this is a temporary bug that is going to be fixed in MS's Nov bug bash or if changes to Avast is needed to get it to work again.