Phil Seamark does some troubleshooting:
When troubleshooting slow DAX queries, sharing the right diagnostic information with an expert can make all the difference. That’s where a DAXX file comes in. This special file format is created using DAX Studio. It bundles essential metadata and performance details without exposing query results. It’s perfect for collaborative optimisation.
Read on to learn more about what a DAXX file is and how it can be useful in the performance tuning process.