Inconsistent or No animations without adding delays.

[dynstat]

I need to show the Contents to appear with sliding animation in real time (only when I receive the data).

Imitating the problem:
In the code below, I have added a column named "left_column" and appending the new Container controls to it with some pre-defined "offset" and "animate_offset" values and then updated the "left_column".
Now on the very next line, I change the "offset" value of the Container to something else, to animate it.

Expected result should show the animation of all 3 containers, but the result shows either no animations or inconsistent animation by animating any one or two of the containers only.

But, when I add (or uncomment in the below code) "sleep(0.1)" statement just after every left.col.update() (after appending a new Container control to "left_column"), all 3 animations seem to work as expected.

So what could be the better approach to acheive this without using sleep() ?

CODE:

from time import sleep
import flet as ft


left_col_ctrl_indx = 0  # index number to to track the last appended control


def m(page: ft.Page):
    def handler(e):
        print("handler func START")
        global left_col_ctrl_indx
        # left_col corresponds to the left_column control added in gui file (start_gui.py)
        left_col: ft.Column = page.controls[1]

        left_col.controls.append(
            ft.Container(
                content=ft.Text(f"Text 1", color="white"),
                bgcolor="blue",
                border_radius=2,
                offset=ft.transform.Offset(-2, 0),
                animate_offset=ft.animation.Animation(400),
            )
        )
        left_col.update()
        sleep(0.1)
        left_col.controls[left_col_ctrl_indx].offset = ft.transform.Offset(
            0, 0
        )  # left_col_ctrl_indx = 0

        left_col_ctrl_indx += 1
        left_col.update()
        # sleep(0.1)  # SLEEP

        left_col.controls.append(
            ft.Container(
                content=ft.Text(f"Text 2", color="white"),
                bgcolor="orange",
                border_radius=2,
                offset=ft.transform.Offset(-2, 0),
                animate_offset=ft.animation.Animation(400),
            )
        )
        left_col.update()
        # sleep(0.1)  # SLEEP
        left_col.controls[left_col_ctrl_indx].offset = ft.transform.Offset(0, 0)

        left_col_ctrl_indx += 1

        left_col.update()

        left_col.controls.append(
            ft.Container(
                content=ft.Text(f"Text 3", color="white"),
                bgcolor="green",
                border_radius=2,
                offset=ft.transform.Offset(-2, 0),
                animate_offset=ft.animation.Animation(400),
            )
        )
        left_col.update()
        # sleep(0.1)  # SLEEP
        left_col.controls[left_col_ctrl_indx].offset = ft.transform.Offset(
            0, 0
        )  # left_col_ctrl_indx =2
        left_col_ctrl_indx += 1

        left_col.update()
        print("handler func END")

    # add/update controls on Page
    page.theme_mode = "light"
    # page.theme_mode = "dark"
    page.auto_scroll = True
    page.scroll = ft.ScrollMode.ALWAYS
    page.window_height = 650
    page.window_width = 600

    page.appbar = ft.AppBar(
        title=ft.Text("TEST APP"),
        center_title=True,
        bgcolor=ft.colors.BLUE,
        color=ft.colors.WHITE,
    )
    start_bt = ft.ElevatedButton(
        text="START",
        on_click=handler,
    )
    page.add(ft.Row(controls=[start_bt], alignment=ft.MainAxisAlignment.CENTER))

    left_column = ft.Column(
        width=370, height=450, scroll=ft.ScrollMode.ALWAYS, auto_scroll=True
    )

    page.add(left_column)
    page.update()


if __name__ == "__main__":
    print("starting gui")
    ft.app(target=m)