Unmerge: "Already being unmerged" message appears but unmerge never completes #108372
Description
Environment
SaaS (https://sentry.io/)
Steps to Reproduce
Environment
- Sentry SaaS
- Grouping Config: newstyle:2026-01-20
- Merged Issues panel (experimental feature)
Description
When attempting to unmerge fingerprints from a merged issue, selecting fingerprints and clicking "Unmerge" briefly shows the message "Already being unmerged" and then nothing happens. The fingerprints remain merged and no changes take effect, even after waiting 24+ hours.
Steps to Reproduce
- Open an issue that has multiple fingerprints in the "Merged Issues" panel
- Select one or more fingerprints using the checkboxes
- Click "Unmerge"
- Observe: "Already being unmerged" message appears briefly
- No changes are applied — fingerprints remain merged
Expected Behavior
Selected fingerprints should be unmerged into separate issues.
Actual Behavior
The UI displays "Already being unmerged" and no unmerge occurs. The issue remains in its merged state indefinitely.
Additional Context
- The issue contains ~27 merged fingerprints (mix of automatic "merged by Sentry" and others)
- Native (C++) crash events using minidump mechanism
- This may be related to Unmerging Merged Issues not working #56334 where unmerge was previously confirmed broken
Impact
Customers cannot separate incorrectly grouped issues, leading to noisy issues that combine unrelated errors. The only current workaround is deleting
the issue entirely and losing historical data.
Expected Result
The issues should be unmerged.
Actual Result
"Unmerge" briefly shows the message "Already being unmerged" and then nothing happens. The fingerprints remain merged and no changes take effect, even after waiting 24+ hours.
Product Area
Issues
Link
DSN
No response
Version
No response