I more recently noticed this problem, perhaps over the past several weeks. I have my home theater PC, running Windows 10, connected via TeamViewer. When it first boots, it will sit at a Windows login screen. I have set up TeamViewer for unattended access, so I do see it on my list of available computers.
However, after a short period of time, OR if the computer was unlocked but then reverts to a lock screen, I will lose the ability to access Teamviewer again. I am quite certain it was not always like this.
Any ideas?