As the error message in your inspect suggests, the resource dash_renderer.[some numbers].js was not loaded.
I can only guess without seeing your code, but it’s probably trying to load that resource from the “root”, i.e. the part of the url that you blacked out + the name of the .js file, but missing the “/dashapp/” part.
If that is the case, you might be able to fix it by adding the requests_pathname_prefix to the dash.Dash() call, e.g.:
app = dash.Dash(your_current_argumentes, requests_pathname_prefix='/dashapp/')
See also the replies from nedned in this thread.