Python - textual - question marks instead of borders in dos prompt

Question

I am running my python code in vs code and it displays fine

but in a windows command line I get question marks where borders should display

I use a tutorial code:

class Hello(Static):
    BORDER_TITLE = "Hello Widget"

    def on_mount(self) -> None:
        self.next_word()
        self.border_subtitle = "Click for next hello"

    def on_click(self) -> None:
        self.next_word()

    def next_word(self) -> None:
        hello = next(hellos)
        self.update(f"{hello}, [b]World[/b]!")

and here is the css

CustomWidget {
    width: 40;
    height: 9;
    padding: 1 2;
    background: $panel;
    color: $text;
    border: $secondary tall;
    content-align: center middle;
}

so I believe it is an utf-8 issue, but how could I fix this ?

this character ▶ does display as a ?

thanks for your help