App-to-Space assignments sometimes swapped after macOS restart when using named Spaces

[simensol]

I’m using Spaceman to name and manage Spaces (e.g. “Work” and “Home”), and I rely on macOS’s built-in app assignment feature:

Dock → Right-click app → Options → Assign To → This Desktop

Issue

After restarting macOS, app assignments are sometimes swapped between Spaces. This does not happen on every restart and appears somewhat random, but occurs often enough to be disruptive. This has been a long-standing issue observed across multiple macOS / OS X versions.

Example:

• Before restart:
  • Space “Work”: work-related apps assigned
  • Space “Home”: personal/home apps assigned
• After restart (occasionally):
  • “Work” Space contains apps previously assigned to “Home”
  • “Home” Space contains apps previously assigned to “Work”

It seems like app assignments may be preserved by Space index/order rather than by the logical Space identity or name, and that when Spaces are recreated or reordered during startup, apps can end up attached to the wrong Space.

Expected behavior

Apps assigned to a Space should remain associated with the same logical (or named) Space across restarts.

Actual behavior

After some macOS restarts, apps are assigned to the wrong Space.

Notes

• Occurs intermittently / non-deterministically
• Long-standing issue across multiple macOS / OS X versions
• Only observed when using named Spaces via Spaceman
• macOS version: 26.2 (25C56)
• Spaceman version: 1.13.0

Happy to provide logs, repro attempts, or additional details if helpful.

[ruittenb]

Hello @simensol,
Some questions:

• do you use one display or more than one?
• You write:

“Work” Space contains apps previously assigned to “Home”
“Home” Space contains apps previously assigned to “Work”

Are all apps assigned to the wrong space or just some of them?

[simensol]

Hi @ruittenb, thanks for looking into this.

To answer your questions:

• I use both setups:

  • At work: MacBook + one external display
  • At home: MacBook internal display only
    I believe the issue happens in both cases.

• When it occurs, it’s not just a few apps:
  all apps assigned to each Space end up assigned to the opposite Space.
  So effectively the two Spaces swap their app assignments entirely.

Current workaround:
When this happens, I rename the “Work” Space to “Home” and the “Home” Space to “Work” in Spaceman, which restores the expected behavior without reassigning each app manually.

[ruittenb]

Thank you. This confirms my suspicion that the space name <=> space number mapping is not retrieved correctly. I will look into this.

[ruittenb]

Hello @simensol , could you please try version 1.13.1 and tell me if this works?
https://github.com/ruittenb/Spaceman/releases/tag/v1.13.1

[simensol]

Hi @ruittenb, thanks for the update.

I’ve installed version 1.13.1 and will test it over the next few days (including restarts). I’ll report back once I’ve had a bit of time to see whether the issue still occurs.

Appreciate you looking into this!

[simensol]

Hi @ruittenb, I’ve now tested v1.13.3 over the weekend. Unfortunately the issue still occurs.

Setup during testing:

• No external display (MacBook internal display only)
• No macOS restarts during this period

Observed behavior:

• The Spaces (“Work” and “Home”) swapped their app assignments twice
• When it happens, all apps assigned to each Space are swapped, not just some

So this seems to still happen even without restarts or display changes.

[ruittenb]

Hello @simensol , please try version https://github.com/ruittenb/Spaceman/releases/tag/v1.13.4, it fixes a bug that was introduced in v1.13.1

[simensol]

Due to #22, I can't tell whether the fix works or not, since the names now disappear.

[ruittenb]

Hello @simensol , could you please try version 1.13.8 and let me know if this fixes the problem? https://github.com/ruittenb/Spaceman/releases/tag/v1.13.8

[simensol]

Hi @ruittenb, thanks again for the update.

I’ve installed version 1.13.18 and will test it over the next week.