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:

• PunE
• Pune
• pune
• PUNE

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:

1. Is this the expected behavior of Power BI during data loading/modeling?
2. If this is expected behavior, is Microsoft/Power BI working on any changes or improvements to preserve the original casing of text values?
3. Is there any way to preserve the exact casing of each source value?
4. 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.

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