Issue with Type Conversion and CSV?

Gjakovasc 
There's culture applied
1. on import, in power query. If not specified it defaults to the current system
2. after importing the value there's a display culture that doesn't have to mutate the underlying data type. Like date-times are integers/floats under the hood, but you can set them to display in any text format.

You can use the optional culture parameter set to en-US Which tells it use that locale/culture's rules for converting text to numbers.

   #"Numbers from en-US" = Table.TransformColumns(
        Source,
        {
            {"Number", each Number.FromText(_, "en-US"), type number}
        }
    ),

hopefully this solve the problem.