Unable to disable or modify priority labels

MR: Pending

Description

As a project maintainer or developer, I want to be able to un-prioritize, subscribe to labels, and promote labels consistently across GitLab, so that I can effectively manage workflows and receive notifications for important labels.

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Current behavior:

• Users are unable to perform certain actions on prioritized labels, including:
  • Un-prioritizing (removing from the prioritized list)
  • Subscribing/unsubscribing to notifications for prioritized labels
  • Promoting to group label
• This occurs even when the user has sufficient permissions (Developer or Maintainer).
• The star icon button press results in no action on a prioritized label

Expected behavior:

• Users with appropriate permissions should be able to:
  • Un-prioritize any label they have previously prioritized.
  • Subscribe/unsubscribe to prioritized labels without error.
  • Promoting to group label
• Pressing the start icon button on a prioritized labels should work the same as it does for non-priority labels

Steps to reproduce:

1. Navigate to Project → Issues → Labels.
2. Create a new label or select an existing one.
3. Click the star icon to prioritize the label.
4. Attempt to click the star again to un-prioritize → action fails / no effect.
5. Attempt to subscribe to the prioritized label via the subscribe button → action fails / not applied.
6. Attempt to click the dropdown next to the label to promote → / no effect

Additional information:

• Issue appears in GitLab.com SaaS, as well as a working version of v18.2.5-ee (likely other's as well, these are my two test cases)
• Not tied to specific browser, reproducible in Chrome/Firefox (latest).
• Known limitations exist with subgroups and archived labels, but this issue occurs outside those cases.

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Acceptance criteria

• Users can successfully un-prioritize a label by clicking the star icon again.
• Users can subscribe/unsubscribe to prioritized labels without error.
• Behavior is consistent across groups, subgroups, and projects.
• Archived labels remain excluded from prioritization/subscription actions (by design).

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Implementation plan

• Investigate frontend actions tied to the star (prioritization) and eye (subscription) icons on the Labels page.
• Verify whether API calls are correctly triggered when interacting with prioritized labels.
• Add automated tests for un-prioritization and subscription actions on prioritized labels.
• Confirm behavior for subgroup projects and document any remaining limitations.

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