Data Flow random refresh issue

[Priyamxylem]

For the past two months, I have been experiencing intermittent issues with the existing dataflow. At times, the refresh completes successfully, while at other times it fails with errors, even though there are no apparent issues with the connection or authentication. From a logical and configuration standpoint, everything appears to be correct.

The dataflow uses simple SQL tables, and authentication is configured through the Virtual Network Gateway. I would like to understand if there is any additional configuration, limitation, or factor that I might be overlooking which could be causing this inconsistent behavior.

@PowerBI @powerbi3 @npowerbi @powerbi2 

[v-dineshya]

Hi @Priyamxylem ,

Thank you for reaching out to the Microsoft Community Forum.

Please try below things to fix the issue.

1. Please share latest failed refresh error (ActivityId, RequestId, the pbi.error JSON).

2. Run VNet “Troubleshoot network” to both your SQL host and the Fabric endpoints on TCP/1433 and share screenshots.

3. Please confirm whether your dataflow uses referenced queries or writes to Lakehouse/Warehouse. If yes, validate that egress rule for 1433 is open from the VNet gateway subnet to Fabric.

4. If you are using Dataflow Gen1 and using OAuth. try to move the logic to Dataflow Gen2 or a semantic model to avoid mid‑stream token expiry.

5. Set up a Power Automate flow to retry once or twice on failure.

6. Filter earlier, remove unused columns, avoid bmany-to-many merges; if you are using incremental logic, ensure filters fold to SQL.

I hope this information helps. Please do let us know if you have any further queries.

Regards,

Dinesh

[rohit1991]

Hii @Priyamxylem 

Check gateway performance metrics, increase timeout if needed, review SQL server blocking/long-running queries, and stagger refresh schedules to avoid concurrency spikes. Also ensure the gateway and dataflow engine are on the latest version.