Jon, I believe you have misunderstood. The issue is that encrypted files are magically being decrypted. I highly doubt AxCrypt decrypts all your encrypted files simply because the user logs off/restarts their machine.
I was stating that decrypted files are again encrypted once the user logs off; not the other way around. But it seems your issue is something else.
The magical decryption doesn’t happen on any of my machines (two at home, one at work) so I’m guessing there’s a problem with your configuration.
As we’re all customers on here it may be quicker to get your problem solved by emailing support because what you’re describing is atypical.