Report Builder - XSLT DataTransform

Hello,

we are currently migrating current SSRS solution to PowerBI paginated reports and we are struggling with XSLT transformations applied in a few reports.  Does anyone have experience with XSLT in PBI?

When I open a current report in Visual Studio, its DataTransform property links to an XSLT file. When I run the report and export an XML file, XSLT transformations apply without any issues and XML file is generated.

When I open the same report in PBI Report Builder, its DataTransform property links to the same XSLT file. When I run the report and export an XML file, it throws an error.

Am I missing something? According to this Microsoft Docs page that also applies to PBI Report Builder, one should be able to perform XSLT transformations even in Report Builder. Unfortunately, I was not able to find any information on the web nor this community forum.

Last but not least, I am describing a local experience as it is currently not advisable to carry on with migration to PBI Service. Supposing I am able to solve this issue with your help, how does one publish an XSLT file into PBI Service?

Thanks so much for any info!