Graph Values Keep Doubling on Refresh – Possible Data Duplication or DAX Issue

[Fyousif92]

Hi Power BI Community,

I’ve created a diversity dashboard, and I’m running into a strange issue: some of the values in my charts (e.g., bar charts) keep doubling seemingly at random. This happens sometimes in Power BI Desktop, and also after I publish the report to the Power BI Service.

A few things I’ve noticed:

• The values appear to multiply (double, triple, etc.) as if data is being duplicated during refresh or interaction.

• I’m using a mix of Power Query transformations and DAX measures.

• No use of volatile functions like RAND() or NOW().

• The issue is intermittent – not every refresh causes it, but it happens enough to be a problem.

• I’ve checked the relationships, disabled Auto Date/Time, and I’m not intentionally appending data.

What I’d appreciate help with:

• What could cause this kind of behavior where data looks compounded after refresh?

• Could it be related to Power Query logic, like reappending the same dataset unintentionally?

• Any best practices to debug step-by-step whether it’s from the ETL steps or a logic issue in DAX?

I’d be happy to share snippets of my M code, measures, or screenshots. Thanks so much!

[Akash_Varuna · Accepted solution]

Hi @Fyousif92 This issue might stem from unintentional data duplication in Power Query or incorrect DAX aggregations. Check Power Query steps for accidental appends and validate relationships to avoid many-to-many joins. Review DAX measures for unnecessary iterations or summations.

[Anonymous]

Hi @Fyousif92,

Thanks @danextian  and @Akash_Varuna  for addressing the issue.

we would like to follow up to see if the solution provided by the super user resolved your issue. Please let us know if you need any further assistance.
If our super user response resolved your issue, please mark it as "Accept as solution" and click "Yes" if you found it helpful.

Regards,

Vinay Pabbu

[Anonymous]

Hi @Fyousif92,

we would like to follow up to see if the solution provided by the super user resolved your issue. Please let us know if you need any further assistance.
If our super user response resolved your issue, please mark it as "Accept as solution" and click "Yes" if you found it helpful.

Regards,

Vinay Pabbu

[Anonymous]

Hi @Fyousif92,

we would like to follow up to see if the solution provided by the super user resolved your issue. Please let us know if you need any further assistance.
If our super user response resolved your issue, please mark it as "Accept as solution" and click "Yes" if you found it helpful.

Regards,

Vinay Pabbu

[danextian · Accepted solution]

hi @Fyousif92 

If this behavior occurs in M, it's most likely due to a merge operation where multiple rows from the right table match each row on the left. As a result, the left-side rows are duplicated based on the number of matching rows.

If it happens in DAX, it's more difficult to diagnose without examining the specific measures (including any referenced ones) and the structure or contents of the tables involved.

[Akash_Varuna · Accepted solution]

Hi @Fyousif92 This issue might stem from unintentional data duplication in Power Query or incorrect DAX aggregations. Check Power Query steps for accidental appends and validate relationships to avoid many-to-many joins. Review DAX measures for unnecessary iterations or summations.