Loading Animation Lost in Docker

Dash Python
1

Hi, I build an app with default circle loading spinner. It worked perfectly locally, but when I put it into Docker and deploy on a Kubernetes cluster, the loading animation was lost… Tried incognito mode, not working, F12 showed no error and css files loaded fine, can’t figure out why…

My Dash version is (checked, same in docker)
dash==3.0.2
dash-bootstrap-components==2.0.0

For code side, used

        layout = dcc.Loading(
            id="loading-spinner",
            type="circle", 
            fullscreen=True,
            children=html.Div(...

and

app = dash.Dash(__name__, external_stylesheets=[dbc.themes.BOOTSTRAP, dbc.icons.BOOTSTRAP])

Could anyone help on this? Thank you!