Critical Bug: Firestore Query Returns No Data Despite Correct Setup

[RKBaoDev]

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• I give permission for members of the FlutterFlow team to access and test my project for the sole purpose of investigating this issue.

Current Behavior

Hello,
When I set up a Backend Query (Query Collection) on any list widget (ListView, GridView, Column) to fetch a list of documents from Firestore, the query returns an empty list in the Test Mode.
Specifically on my "MatchPlayPage":
I have a Column with a Query Collection on my "Questions" collection.
The query is correctly filtered using a Document Reference from the page's main document (matches Document).
The result is always an empty list, and my Text widget inside shows the "Default Value" ("Erreur de chargement").
This happens even when I remove all filters.
I have confirmed that the data exists in Firestore, security rules are open, and all schemas/references are correct. The app is simply unable to read any list of documents.

Expected Behavior

The Backend Query on the Column widget should successfully fetch the list of "Questions" documents from Firestore that match the filter.
The Text widget inside the Column should then display the question_text from the first document of the returned list.
In short, the dynamic children generation should work and display the data retrieved from the Firestore query.

Steps to Reproduce

1. Go to the page named PlayOptionsPage. 2. In Test Mode, select the "Solo" mode. 3. Select any of the free themes (e.g., "Histoire" or "Géographie"). 4. Click the "Lancer la Partie" button. 5. You will be navigated to the MatchPlayPage. 6. Observe: The page shows the default text "Erreur de chargement". This text is the default value for a Text widget that is supposed to display a question. This proves that the Query Collection for "Questions" on this page is returning an empty list. 7. Expected: The page should display the text of the first question from the "Questions" collection that matches the selected theme.

Reproducible from Blank

• The steps to reproduce above start from a blank project.

Bug Report Code (Required)

IT4gi8rlvJRgoctJ7qqNce9WpCQsJj41UIc0st4bGAsdGOvrBu0hP8zSXFJpXdO4aVNcM1qboEEzpPSJiYXXU/cFBymZGrk4/pducj30e2i7VY/XDLu8X0FTL+FmIWqe5MO72R1/NfpeWF1k7XGmB9myaDbDFOu/Zwh9f6PHaOI=

Visual documentation

Environment

- FlutterFlow version: v6.3.11
- Platform: Web
- Browser name and version:Chrome Version 141.0.7390.108
- Operating system and version affected: MacOS Sequoia 15.7.1

Additional Information

No response

[Alezanello]

Hi there!

In most cases (about 99% of the time), this issue is caused by incorrect Firestore index settings. You’ll need to adjust your indexes until they match your app’s specific needs.

Additionally, if you’re using the Users collection as shown above, we recommend setting all the rules in that collection according to your user collection rule set for consistency and proper access control.

[Alezanello]

Closing this issue since we haven't heard back from you. If you are still facing the problem please submit a new issue. Thank you!