Version

I'm using the current trunk (affects 1.21.0).

Known issues / Existing issues / Advanced Preferences

I've checked Known issues, Existing issues and Advanced Preferences — no match.

Operating system

macOS

Operating System Version

macOS 26 (Darwin 25.5.0)

Reproduction steps

1. On macOS, enable Fullscreen breaks (overlay breaks, not "show breaks as regular windows").
2. Trigger a Mini or Long break and do not interact with it.
3. Watch the break window for ~10 seconds.

Reproduces how often: 100%

Expected Behavior

A fullscreen break should stay fullscreen on its own Space, with the menu bar hidden, until the break ends or is skipped/finished.

Actual Behavior

The break window correctly enters fullscreen on its own Space, but a few seconds later — with no user interaction — it silently drops out: the menu bar reappears and the window is no longer on its dedicated Space. This also weakens strict-mode breaks, since the menu bar and other Spaces become reachable again.

Additional information

Root cause (confirmed) and fix in an attached PR: each break window is given both setKiosk(true) (NSWindowCollectionBehaviorFullScreenPrimary, owns a dedicated Space) and setVisibleOnAllWorkspaces(true) (NSWindowCollectionBehaviorCanJoinAllSpaces). These two collection behaviors are mutually exclusive; macOS honors kiosk briefly, then reconciles by ejecting the window from its Space. The fix skips setVisibleOnAllWorkspaces(true) for kiosk-fullscreen break windows on macOS.

Code of Conduct

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