SharePoint List Automatically Changing Project ID Values in Backend Used by Power Apps!

This behavior is consistent with downstream processes or workflows updating SharePoint list items after the initial save, rather than with a known SharePoint Online indexing or threshold bug.

From the provided information, two patterns in SharePoint/Power Platform can cause values that were initially correct to later become blank or changed:

1. Workflows or automation updating other columns
   • When a workflow (for example, a SharePoint 2013 workflow) updates a column such as Status on an item, it can unintentionally affect other fields.
   • Specifically, if a Multiple lines of text column has Append Changes to Existing Text enabled, SharePoint internally updates that column with an empty value when another column is updated by the workflow. This results in that text field becoming blank in the workflow output, even though it previously contained data.
   • This demonstrates that background processes (workflows, Power Automate flows, or Power Apps logic) can modify existing values after the initial save without any manual edits in the SharePoint UI.
   In the documented case, the workaround is to disable automatic workflow status updates and manage status explicitly in the workflow logic. That pattern generalizes: any automation that touches list items can overwrite or clear fields if not carefully scoped.
2. Power Apps environment variables and SharePoint data source references
   • When using environment variables and solutions, data source references (including SharePoint lists) can be misaligned after import into another environment.
   • SharePoint does not fully support ALM scenarios in this context. Metadata and data source info can be wrong in the target environment, and Power Apps Studio may still point to the original environment’s list.
   • If two environment variables resolve to the same SharePoint URL, they can collapse into a single value on import. This can cause the app to read from or write to an unintended list or column mapping.
   • In practice, this can appear as “random” changes to existing items because the app is connected to the wrong list or mis-mapped columns, and subsequent edits or background logic update the wrong records.
3. Implications for the described scenario
   • The fact that Project IDs and other fields were correct at first but changed later strongly suggests:
     • A workflow, Power Automate flow, or Power Apps rule is updating items after creation (for example, on status change, recalculation, or periodic sync), or
     • The app’s data source references (especially when using solutions and environment variables) are misconfigured so that later edits target different items or lists than originally intended.
   • SharePoint list thresholds and indexing issues typically affect querying and performance, not silent value changes in already stored items.
4. Recommended checks based on these patterns
   • Review all workflows/flows associated with the list:
     • Look for actions that update the Project ID or related fields, or that update any column on the item (such as Status) which could indirectly affect other fields.
     • If using SharePoint 2013 workflows, consider disabling automatic workflow status updates and explicitly controlling status updates.
   • Inspect Power Apps logic:
     • Confirm that the app writes to the intended list and columns in the current environment.
     • If using solutions and environment variables, verify that each SharePoint URL and list variable resolves to a unique, correct value and that no two variables collapse to the same URL.
   • Check for any background or scheduled processes (flows, jobs, integrations) that might re-sync or “fix” data and inadvertently overwrite Project IDs.

These are the documented, supported mechanisms by which SharePoint list values can be modified after initial storage without direct user edits in the list UI.

References:

• Workflow that uses the SharePoint 2013 Workflow Platform Type contains blank values in output from the "Multiple lines of text" column
• Data source references based on environment variables aren't updated during solution import