Hi @Taylor, Damien ，
To be honest, PowerShell is beyond my abilities. The following content is for reference only, and may not be of significance to resolving the issue:
If updating the connection string and the data source makes use of stored credentials, you need to provide the account password.
To update a data source connection string:
$dataSources.ConnectionString = 'data source=myCatalogServer;initial catalog=ReportServer;persist security info=False'
To change the data source credential type:
$dataSources.DataModelDataSource.AuthType = 'Integrated'
To change the data source username/password:
$dataSources.DataModelDataSource.Username = 'domain\user'
$dataSources.DataModelDataSource.Secret = 'password'
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