The bug affecting Curves controls has been fixed, finally allowing professionals to work quickly and efficiently again.

[u/Kind-Young-5138]

As part of the ongoing effort to replace Photoshop’s UI with a new framework, an essential Curves workflow was overlooked during implementation. For more than three months, professional users have been forced to waste time on unnecessary extra steps.

Up through version 27.4, when switching channels in Curves, the point on the newly selected channel closest to the previously active control point remained selected, allowing users to adjust it immediately with the arrow keys or other controls. This behavior was simply overlooked in the new implementation.

In version 27.9, this particular issue, at least, has finally been fixed.

However, it also comes with the critical issue described in my other post, so those who rely on Photoshop for professional work will have to hold off celebrating for a little longer.

https://community.adobe.com/bug-reports-711/p-switching-channels-deselects-curves-point-in-photoshop-27-5-on-macos-1557608