Merged Field From Power Query Not Populating on Report Builder Side

Hi,JJ51 . I am glad to help you.

Based on your description, here are my guesses about the problem you are experiencing and your operation.
In fact I am puzzled by some of the terms in your description, so please check if my guesses are correct and correct them promptly.

1. In Power Query and Report Builder, everything works fine initially.
Here in Report Builder is normal, here Report Builder refers to what, refers to Power BI desktop in the report view view mode, or refers to the production of paged reports using the report builder software, I personally prefer the former!
2. However, after the service refresh, some fields become empty.
Here the service refresh refers to what, is that you these report production work are in the power BI service to complete is it, that is, you refresh is power bi service

3. you refreshed the service after the problem, and then downloaded the pbix file and use Power BI Desktop to open it, at this time in the Power query everything is normal, but in the Report Builder (that is, I think the report view view mode) in the empty, at this time the problem still exists.
4. You then clicked Refresh in Desktop, the problem is solved, Report Builder view (Report View view mode) in the field will be filled correctly, there is no longer appear before the refresh of the field data appears empty values!
To summarize, my guess is that you created the connection to the data source, the relational model and produced a report on power BI Service and subsequently downloaded it as a pbix file and opened it locally in Power BI Desktop.

I think it's really strange that this is happening. power BI Service acts as a Microsoft managed cloud reporting server where we can use some of the cloud services in it (including power query online)
You can see the Power Query service (including Power BI service) in each platform through the following links.
URL:The Power Query user interface - Power Query | Microsoft Learn

It is important to note that
The data preview in Power Query is only a snapshot of the data displayed, the real data loading and applying will only take effect after clicking the “Apply” button. Therefore, just because the data you see in Power Query is normal does not necessarily mean that the data you load into the report will be normal, the data you see in the Report View will be the main criterion.
This is also the reason why you mentioned: why the data processing in Power Query shows normal, but some of the data will be empty after loading into Power BI desktop.
In fact, this is a very confusing fact, and many users have similar thoughts as you: why I have successfully processed the data correctly in Power Query, but have problems loading it in Desktop.
This is because the actions you perform in Power Query without clicking the final Apply button are previews and the actual data has not yet been processed successfully.

Below are my suggestions on how you can solve the problem:

You can save the .PBIX file downloaded from Power BI Service as a new file in Power BI Desktop and republish it to Power BI Service. Ensure that the data gateway is configured so that the server side can access the data source correctly. This method can help resolve issues due to the server-side refresh mechanism.
URL:
Query overview in Power BI Desktop - Power BI | Microsoft Learn
Manage Data Preview (Power Query) - Microsoft Support
 

I hope my suggestions give you good ideas, if you have any more questions, please clarify in a follow-up reply.
Best Regards,
Carson Jian,
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