Dell UltraSharp UP3221Q User Manual page 69

If you press any button other than the Power Button, the following message will
appear depending on the selected input:
NOTE: The message may be slightly different according to the
connected input signal.
If either Thunderbolt (90 W), HDMI, or DP input is selected and the
corresponding cable is not connected, a floating dialog box as shown below
appears.
NOTE: The message may be slightly different according to the
connected input signal.
When the monitor is under DP/HDMI input and a Thunderbolt™ 3 Active cable is
connected to a notebook that supports DP Alternate Mode, if
Thunderbolt (90 W) is enabled, the following message appears:
Auto Select for
Operating the Monitor
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