Hi @ibourega ，
// It does not read the .csv file properly all the time ;
Do these csv files have the same delimiter and character set? Try adjusting the File Origin options and the delimiter options.
// and the main issue is the very long time it takes to update the data.
Consider sharing the m-code of the transformation step where the performance problem occurs. It would be a good idea to attach some screenshots so that we can understand it better. Please mask sensitive data before uploading. Thanks.
Best Regards,
Gao
Community Support Team
If there is any post helps, then please consider Accept it as the solution to help the other members find it more quickly.
If I misunderstand your needs or you still have problems on it, please feel free to let us know. Thanks a lot!
How to get your questions answered quickly -- How to provide sample data in the Power BI Forum -- China Power BI User Group
