Concierge chat shows no message history when opened from Inbox

[MelvinBot]

Problem

On NewDot web, opening the Concierge chat from the Inbox shows an empty conversation with no message history, even though prior Concierge history exists and should be displayed.

Steps to reproduce

1. Go to Inbox
2. Search for / open the Concierge chat

Expected result

The Concierge chat loads and displays its existing message history.

Actual result

The chat opens empty — no history is shown.

Platform

• Web

Notes

• Observed 2026-07-29 on a large account (high report/expense volume).
• Customer details intentionally omitted.

Slack thread: https://expensify.slack.com/archives/C05LX9D6E07/p1785167386765389

Issue Owner

Current Issue Owner: @fedirjh

[BartekObudzinski]

I found the root cause after tracing the Concierge chat flow. Search Router creates an optimistic report when the Concierge report is missing from the report collection, even though conciergeReportID is already available, so the chat opens without its history. It looks like a race condition, and I’ll work on a fix now

I started working on the implementation, but during the investigation I tried reproducing the issue on another account using a regular session instead of Supportal, and everything worked correctly. I also tried including accountIDList in OpenReport, but it still returned 403, so I reverted that change.

To isolate the issue, I temporarily forced Search Router to open the existing conciergeReportID instead of the optimistic report, and the Concierge history loaded correctly through Supportal. This confirms that the problem is specific to the Supportal flow in Auth. OpenReport exits before resolving the existing DM, so it returns neither preexistingReportID nor reportSummary, and the App middleware cannot replace the optimistic report. The proper fix should allow Supportal to resolve an existing DM while still preventing it from creating new chats