Hello,
Thanks for sharing your solution, it may be helpful for other users. Anyway, if a framework, CMS or any PHP code is adding extra information to a download, the most common issue is some wrong configuration or some PHP chunks or logs that are being added wrongly.
About your question, there's no option to filter the forum posts by a user, but you can write your username in the search field (https://www.phpdocx.com/search/).
Regards.