Excel VBA OLEDBConnection.CommandText doesn't work with LIKE operator

Question

I need your help to match my fallacy (or just stupidity) by creating a simple SQL Query string in Excel VBA. Connection 3 is a Microsoft SQL database on a separate server. If I use the operator "=" the code work, when using "LIKE" instead runtime error 1004 occur...

This one works fine

With ActiveWorkbook.Connections(3)
        .OLEDBConnection.CommandType = xlCmdSql
        .OLEDBConnection.CommandText = "SELECT * FROM testSystems WHERE **partGroup='CLV'**"
        .Refresh
        
        Debug.Print .OLEDBConnection.CommandText
    End With

This one exceeds in runtime error

With ActiveWorkbook.Connections(3)
        .OLEDBConnection.CommandType = xlCmdSql
        .OLEDBConnection.CommandText = "SELECT * FROM testSystems WHERE **partGroup LIKE 'CLV%'**"
        .Refresh
        
        Debug.Print .OLEDBConnection.CommandText
    End With

I expecting that the LIKE statement works also in this case...