Problem
Since the update to macOS Tahoe 26.1, you may experience user interface (UI) hangs and stutters in Cubase and Nuendo.
Cause
If the channel settings window is open in the background with no focus (for instance, because the arrangement window is in the forefront again), saving the project, closing it, and reopening it will lead to the mentioned UI hangs.
Workaround
Ensure that the channel settings window is visible while working with Cubase/Nuendo when the project is supposed to be saved. It can also help to set the window to "always on top" if the screen setup allows.
This issue affects all Cubase versions prior to 15.0.6 and all Nuendo versions.
Since this issue does not occur in older macOS versions, including 26.0.1, we are in contact with Apple to clarify whether this is a planned change.