Shutdown_delay doesn't work

[nricciardi]

Hello, I'm trying to run my Eel application. My application sometimes refreshes page.
I have used the shutdown_delay option to increase time before automatic websocket closing (so the page have time to be reloaded).
I'm using the last Eel version.

EDIT:
There is a conflict between shutdown_delay and close_callback.

EDIT 2:
I have found the problem: close_callback is called also each time page refreshed, but why?