Happens multiple times a day for the past month or so

Running macOS 26.5.2

As Filip's comment above (from May), Undo is still not available for me and several people on my team. Is this being looked at?

Also, when changing tools in the tools palette, the icon remains on the previous tool. For example, when switching from the type tool back to the selection tool (black arrow), my cursor has the properties of the selection tool but remains looking like the type tool.

Please can someone at Adobe acknowledge receipt of this comment and let us know you're looking at these issues.

Subject: Undo permanently greyed out / non-functional — InDesign 2026 (21.4), macOS
Version: InDesign 2026, 21.4 and I also tried installing 21.1 as some users found that fixed it, it did not fix it for me.

OS: macOS Tahoe 26
Issue: Undo has stopped working entirely. Edit > Undo is greyed out / does nothing, and ⌘Z has no effect. [Add if true: History panel is blank; cursor sometimes sticks in the wrong tool; quit hangs and requires force quit.]
Reproduction: Occurs across [all documents / this specific document]. [If you spot a trigger, e.g.: appears related to documents using the Effects panel / neon effect.]
Already tried, with no change:

Restarted machine; quit and relaunched InDesign
Reset preferences (Shift+Option+Command+Control on launch)
Verified ⌘Z is still assigned to Undo in Edit > Keyboard Shortcuts (Default set)
Disabled third-party plugins / font managers
Checked for macOS-level shortcut conflicts

This matches the still-open behavior reported in the "Undo greyed out and History panel blank on macOS" and "21.2/21.3 undo not working, slow quit, import lag" threads, but is now occurring on 21.4 — so it does not appear resolved in the latest release.

Falsely says it's fixed.

Also having this issue -- tech support remotely accessed my computer to fix it, but 30 minutes later, I had the same issue. I did not see this bug addressed as a documented fix in the update I just downloaded.