I have been using an LG 5K display since last spring as second display.
For several months now, the display has had a greenish tint (obvious to my eyes) that makes it unusable for color-judgment work.
Maybe it is an Apple Core Rot thing. Or maybe it is a Photoshop bug, I just can’t tell for sure.
One thing that is clear: if I have an image open in Photoshop, click to another app, then click back to Photoshop, then the image flickers instantaneously, and the green tinge disappears. It occurs with all raw files I work with, and it happens with a newly-opened raw both in the ACR window and once opened. This strongly suggests a Photoshop bug though there could be other explanations. However, I don’t see the issue when I open the same image saved-out as a JPEG. Nor do I see a tinge problem with a JPEG preview in the Finder. Very confusing.
Such problems are why why I stick with proven solutions, that is, my NEC PA302W which has performed faithfully for years and offers true calibration to 14-bit precision internally using the SpectraView II software. That said, maybe if my 2nd display were a NEC, the same issue would exist if it is a general Photoshop bug.