I successfully setup Teamviewer in headless mode for my Raspberry Pi 3 running Raspian. However, I am unable to switch back to the GUI for other folks using the device. Any guidance is much appreciated.
Thank you for your post.
The reason that you're not able to switch from headless properly is because TeamViewer doesn't support switching between terminals.
To make TeamViewer work again you should restart the TeamViewer daemon by running the following command.
sudo teamviewer daemon restart
If you like to use the terminal session and are used to switch we recommend better to use the terminal window from the GUI instead.
Hope this solution works for you.