Date format changes when I take the focus off the input

Question

I don't really know how to solve this problem, when I click on a datepicker to insert a new date and type , when I remove the focus the date format changes by itself.

Video demonstration below:

Date format change

This is what i added to my project :

app.module.ts

 providers: [
            {provide: MAT_DATE_LOCALE, useValue : 'it-IT'}
            ],

Does anyone know if there is a way to fix that?