PyCharm has stopped reopening project files on restart

I am not sure if a recent update of PyCharm or of Windows 10 OS has caused this problem.

Old behavior: I stop work for the day and close PyCharm with the project I am working on and some of its files open and in use. The edit config for the active open file was selected and ready for run/debug use when PyCharm exited. When I next reload PyCharm, the "last in use" state of my work session was restored, open files reopened, edit configs associated with files as usual.

New behavior: PyCharm reloads and the last opened Project is active but NO previously open files and their edit configs are reopened and active.

I have searched everywhere in the various program and project settings and can only find reference to the general feature of reopening the last project in the same or new window/instance.

I am thinking there must be a tweak in the project config files for this project, but cannot find anything that seems to fix this annoying issue.

Thanks for any help with restoring the behavior of having "last opened" files reopened and not just the top level project.