Is complaining and talking about a problem with someone or their behavior considered backbiting (gheebah), which is forbidden?

Backbiting is to mention a Muslim with what he dislikes, and it is one of the major sins. It is permissible to mention a person with what he dislikes in specific situations, including: seeking redress, seeking a fatwa, requesting help in solving a problem, mentioning an oppressor commensurate with his oppression for the purpose of retribution, and mentioning an unknown person without identifying him.