Has Undo changed?

G2.6.2 [1246] macOS 10.13.6 – I’m thinking that using Cmd-Z in a character cell has always only worked for that cell, and used to beep when no more could be undone.

That has changed; now it works globally, a very bad thing.

It should still work that way. Can you describe steps to reproduce?

I will make note of the steps when it happens again.