Check if your remote desktop connection is set to "use all my monitors for the remote session" under the display tab.

Right click on the remote desktop shortcut, choose edit, click on the tab labeled 'display'.  

If you do not see multiple tabs as shown in the video below you may need to click the 'Show Options' arrow in the bottom left.

Uncheck  "use all my monitors for the remote session" then click save from the general tab.

Log off the server then reconnect with the saved remote desktop shortcut.