I've been seeing many people having issues with P3D after installing the latest Windows update. It was only very recently that I began to have problems with my sim. One of the things I recalled about Windows updates is that it undoes any changes you make to their background programs. In other words - you have to reapply those changes after you install an update to Windows. For example - I turn off any and all telemetry services that Windows applies (or re-applies) after an update. I also disable Windows Defender since I have a third-party antivirus. Windows Defender is a good basic antivirus and shouldn't be disabled without another program to take its place. I say again: DO NOT DISABLE WINDOWS DEFENDER WITHOUT A PROPER ANTIVIRUS INSTALLED!
In my case, I noticed Windows Defender was turned back on after the latest update and my system was acting a little strange. My antivirus was taking forever to get permission from Windows to run. When I started P3D, it ran the first time but then I ran into problems with some of my addon aircraft (including my PMDG products). After I disabled Windows Defender and restarted my system, everything seems to be working as it should.
Again, this is in no way recommending you turn off any Windows services. There may be conflicting programs that require the user's attention. Just my two cents.