I have two U2413 and the newest version 1.5.3 Dell UltraSharp Color Calibration Solution.
The second display(big 2 on it with win identify displays) is not treated by the software above as a U2413 with hardware LUT calibration capabilities. The option for the colour spaces "Abode RGB, SRGB REC709.." are not displayed and the option for saving in Calibration 1 or 2 is not given during the calibration process.
However, if I just turn off the first display and start the calibration software again, then the second display is magically treated as it should be, with the colour spaces option and options for saving in Calibration 1 or 2.
Can anyone confirm this as a bug?
One test I will do in the next 12 hours is to connect the displays to different USB 3 Ports - first to USB 3 on the host controller from the motherboard chipset and second to the USB 3 ports on the host controller from the motherboard manufacturer. Might be an enumeration bug if the the displays are on the same USB host controller.