refreshable header issue

scratch_256.py

from nicegui import ui


@ui.refreshable
def app():
    username, set_username = ui.state("")

    with ui.header():

        with ui.tabs().classes("w-full") as tabs:

            app_tab = ui.tab("App")
            settings_tab = ui.tab("Settings")

    with ui.tab_panels(tabs, value=app_tab if username else settings_tab).classes("w-full"):

        with ui.tab_panel(app_tab):
            ui.label(f"Hello {username}!").classes("text-2xl")

        with ui.tab_panel(settings_tab):
            field = ui.input("Username", value=username)
            ui.button("Submit", on_click=lambda e: set_username(field.value))

app()

ui.run(show=False)