The credentials provided for the Snowflake source are invalid

Microsoft have issued a service advisory about this.  They acknowledge the issue and are allegedly working to roll the change back.

PB1154762

Hi Gagana,

Thank you for providing the details. Based on the error, it appears that the Snowflake credentials set up in the Power BI service are not being accepted, even though the refresh history does not display any errors. Please check the following:

Verify that the username, password, and role in the service match those used in Desktop.
Make sure the authentication method selected in the service is the same as in Desktop (such as Username/Password or SSO).
If using DirectQuery, ensure the gateway is properly configured and uses the same credentials.
Sometimes, resetting and re-entering the credentials in the service can resolve this issue.

Kindly refer to the official documents listed below.
Connect to Snowflake with Power BI - Power BI | Microsoft Learn
Power Query Snowflake connector - Power Query | Microsoft Learn

You can also review the related threads which will give you an idea:
Data Source Credentials Issue with Snowflake Direc... - Microsoft Fabric Community
Solved: Re: Snowflake data source refresh errors following... - Microsoft Fabric Community

Thank you and continue using Microsoft Fabric Communtiy Forum.

Hi Gagana 

Can you also confirm that you are connecting correctly when using Power BI desktop? And you can see the queries heading the Snowflake instance.

Hi Gagana,

Just wanted to follow up and confirm that everything has been going well on this. Please let me know if there’s anything from our end.
Please feel free to reach out Microsoft fabric community forum.