German site Prad.de reports that sources close to monitor panel manufacturers told them that the production cost of a 27" 4K 3840x2160 panel is lower or at least equal to that of a 27" 2560x1440 QHD panel. This drives monitor manufacturers to use 4K panels in monitors that are specified as QHD - when panel supply is low, or monitor demand is high.
https://www.techpowerup.com/forums/...ould-be-using-a-4k-panel.245367/#post-3859415
If true this is quite frankly shocking behaviour by the monitor manufacturers involved. They should own up and issue firmware fixes to unlock 4K on the screens or offer refunds if buyers didn't want 4K.