Dell Monitor U4320Q recognized as two monitors

Hallo everybody

I have my NTB Precision 3571 connected to monitor U4320Q via docking station WD22TB4. All drivers and BIOS are updated. Operation system WIndows 11 version 22H2. Monitor is connected via displayport using cable delivered with the docking station. My issue is that the system thinks that I have two external monitors. This means, that in the Windows settings are shown three monitors: 1x NTB monitor and 2x U4320Q.

Sometimes happens that some program appear on the not existing 3th monitor after opening. Also working/setting of my Wacom drawing tablet is tricky.

How to setup the external monitor correctly or remove the not existing monitor from the system?

Thank you for your answer.