Hello Marco,
I am sorry for the late reply.
The issue is with your database field. This field has a character limit which limits the param content; truncating the value of the field. Since your post is very long, this field cannot hold the content. So, I have run this query which updates your database tables.
ALTER TABLE `#_social_stream_item` CHANGE `params` `params` LONGTEXT NULL
Initially, the this field 'params' is using 'TEXT'; in which there is character limit in TEXT format, so after I run this query, it will alter this table field to 'LONGTEXT' in which has greater limit compared to TEXT.
Hope this will help.
Thanks.