I spent some time trying to figure this out, so I am posting it here in hopes Dell can talk to Intel.  Here is the problem:  You cannot change the recommended display resolution of 3840 x 2160 because it is greyed out. 

What is the problem with this? Some native and older applications show tiny, and they are difficult to read.  Specially if you are connecting remotely to help clients. It was giving me a migraine, so I had to resolve it. 

After a fun long chat with Nvidia installing all kind of different drivers that took me nowhere, I tried all kind of things, even resetting the device to the factory defaults... nothing worked.  It was not until I got another laptop without the issue that I was able to determine that the issue is caused by Intel UDX/Iris Xe Graphics Driver version  31.0.101.5333, A11 . After trying several versions I was able to determine that 31.0.101.4255, A09 does not have the issue.  Intel UHD/Iris Xe Graphics Driver | Driver Details | Dell US

Hopefully this post helps someone avoid wasting all the time I wasted.  @Dell, please do not push this update until the driver is fixed.