When the Select widget is first expanded, the initial selected value is out of view when it appears further down in the list of options.
from textual.app import App, ComposeResult
from textual.widgets import Select
class SelectApp(App):
def compose(self) -> ComposeResult:
yield Select.from_values(
range(20),
value=15,
)
if __name__ == "__main__":
app = SelectApp()
app.run()