hey Stefano,
it seems like you disable this setting from backend > Easyblog > settings > comment > integrate tab > Built in comments - NO,
I already help you set to YES, it should display comment form now.
But I noticed you didn't install Komento but it show the Komento tab, can you check with your database > Easyblog table > `#__easyblog_configs` > edit the columns > find this keyword >
comment_komento="1" > if it stored
1 > change it to
0