Second screen on HDMI port of Elitebook x360 1040 G7 only duplicates, but not extends desktop

[fskdb]

I am very happy with my new Elitebook. However, a thing that worked for all my notebooks over the past "ages" is: Connect a second screen via a display port - in this case: HDMI - and then choose within Windows to either extend or duplicate the desktop.

Here, it is different: it duplicates the desktop but I cannot choose to extend it (two independent screens). I do NOT want to use a docking station, this should work natively.

Thanks für any suggestion!

[fskdb · Accepted solution]

The problem is solved. I tried the default way (right-click the desktop, Display settings, or whatever the English name is (I have a German OS). This DID NOT offer to extend the desktop.

Using the settings and enable desktop expansion solved the problem.