This story has a fascinating sub-text: will a reputable mathematics journal, or a professional mathematician, review and critique Mr. Nirbhay Singh Nahar's work?
On the home front: before publishing and promoting that article, I had staked my copyright claim to my original artwork by publishing it here.
Some sites, or their editors, change the title. Presumably the goal is either to pique the interest of a human reader, or to better align with Internet searches. Even if the title is changed, however, if you enter the article into the site's online editor, your original title becomes part of the URL and any hidden tags.
My first writing tip today is: try hard to craft your title both for human interest and for search engines.
My second writing tip is: trust your editor if the title is changed.