Power BI automatically normalizing text casing during data load

Hello everyone,

I am building a Power BI connector that loads data from a server and have observed an unexpected behavior with text values.

For example, the source data contains the following values in the City column:

However, after loading the data into Power BI, all values are displayed as PunE, matching the casing of the first occurrence.

It appears that Power BI treats text values as case-insensitive and preserves the casing of the first occurrence of a particular text value.

My questions are:

Is this the expected behavior of Power BI during data loading/modeling?
If this is expected behavior, is Microsoft/Power BI working on any changes or improvements to preserve the original casing of text values?
Is there any way to preserve the exact casing of each source value?
Since I am developing a connector that retrieves data directly from a server, are there any connector-side measures or transformations I can apply to prevent this behavior?

I have attached screenshots illustrating the source data and the resulting Power BI output.

Excel Table -

Power BI Table which is loaded from above excel file -

Any guidance on how this can be handled at the connector level would be appreciated.

Forum Discussion