This is a known quirk/bug in Railway's environment synchronization and diff engine where a single parent service or configuration discrepancy (such as in the API service) cascades and generates phantom or cascading diffs across unrelated groups, volumes, and services (like api-redis-volume, API Postgres, and empty color/metadata changes).

Because the entire diff view relies on a state tree, a malformed comparison or stale reference on the primary service throws off the diff calculation for everything else linked or grouped under it.

Recommended Workarounds & Fixes

Discard or Re-apply Incrementally: As you noticed, discarding the primary API service diff clears out the cascading noise. If you need to sync changes, try syncing services individually rather than doing a bulk environment sync, starting with the underlying databases/volumes first and leaving the main API service for last.

Hard Refresh / Clear Cache: Sometimes the UI state gets out of sync with the Backboard API. Hard-refreshing your dashboard (Ctrl + Shift + R or Cmd + Shift + R) or logging out and back in can clear out ghost diffs.

Check for Hidden/Injected Variables: For unexpected username/password diffs on services where you never set them, check if a shared reference, plugin default, or template variable is injecting generated credentials during the sync evaluation.

Thanks for your response. On your recommended workarounds:

• Discard or Re-apply Incrementally: This is what I'm currently doing, but having a mix of correct and incorrect diff can lead to critical mistakes. This is a bug I'd rather not keep working around.
• Hard Refresh / Clear Cache: It's not a client-side bug. This bug survives hard refresh and reproduces in different browsers.
• Check for Hidden/Injected Variables: None of those "ghost" diffs are variables. Username and Password are not variables as you can tell from the icon.

The pattern :- Password/Username showing as diff even though you never set them, and other diffs clearing the moment you discard the API one points to those values getting regenerated fresh every time the diff is computed, not actually stored differently. If API's Password/Username come from a generator (like an auto-generated Railway credential) rather than a static value, the diff tool might be re-evaluating that function each time it builds the comparison, so it's comparing against a new random value every render. That'd explain the cascading diffs too, if other services reference that same value.

Easy way to check without touching the sync UI: pull the actual values via CLI :-

railway variables --service API --environment

railway variables --service API --environment

If those match, it confirms it's a bug in the diff computation, not real drift meaning discard-and-resync isn't safe since you can't tell which flagged items are real.

I checked API variables in all environments with the CLI, and none of them included Username or Password.

Huh, okay that kills my theory then. If Username/Password aren't real variables anywhere, then whatever the diff tool is comparing isn't your actual config at all it's probably comparing against some leftover template schema that still expects those fields, even though your service doesn't have them anymore.

Could be from how API was originally set up like if it started from a template that defined Username/Password as expected fields (some DB templates do this), and got changed since, but the sync logic never stopped checking against that old definition. Would explain it showing as "diff" even with nothing actually there to diff it's seeing "expected field missing" and treating that as a change.

did you try to redploy once again and see ?