Can you try download my attached file and replace into this file location and see how it goes?

JoomlaFolder/components/com_easysocial/controllers/events.php

Note : Remember backup your original file before you replace.

Thank's,

After delete event, it goes back on group stream (and not on app event page of group) page but it's fine for me !

I just tested create a new group from your site and created an event in my test group, it seems it redirected correctly when I delete event from your frontend, it will redirected to the group page.

As a gentle reminder, kindly start a new thread if you have any other issue in the future so it will be easier for us to manage your inquiry. I will lock and mark this thread as resolved.