Teamviewer 11 randomly sends Ctrl+C in remote session

I have one tech who is experiencing a strange issue.  When he is connected to a remote computer or server, his session is randomly sending Ctrl+C commands.  We already tried unchecking the send key combinations option under the Actions tab, but it still does it.  We also tried uninstalling and reinstalling Teamviewer.  We launched a command prompt on the remote computer and let it sit there.  The ^C would show up at the prompt about every minute.  Sometimes it stops for a while, but will eventually start up again.  Other times it may not do it at all.  It's very random.  His computer is a Surface Pro 4 with the anniversary edition of Windows 10.  We verified it does it regardless of wheter it is connected to his Surface dock with a wireless keyboard and the type cover removed or disconnected from the dock with the type cover connected.  Any ideas?