Stop date field format changes in report ?

One option is to create a calculated column in Power BI Desktop to format the date as desired, and then use this calculated column in the report instead of the original date column. Here's how:

1. In Power BI Desktop, go to the "Modeling" tab in the ribbon and click on "New Measure".
2. Enter a formula to create a calculated column with the desired date format. For example, if you have a column called "Date", you can use the following formula:

=FORMAT([Date],"dd MONTH yyyy")

1. Save the calculated column and use it in the report instead of the original date column.

Note: If you have many date columns, you will need to create a calculated column for each one, or create a single calculated column that formats all of the date columns as desired.