Explaining and teaching is rather different than mansplaining.
My experiences of mansplaining have been fairly distinctive. I define it as having a male person explaining some task or concept to a person with less privilege, who also has more expertise in that task or concept than the explainer.
For example, I regularly lecture on the physics behind principles of radio communication. Many users of radio systems, from civil service through amateur radio operators, have some ideas as to how things work, often based on lore passed along in licensing classes or from senior operators, or 'rules of thumb' from manuals and texts. Sometimes the information passed along is incorrect, incomplete, or accompanied by pretty goofy explanations.
After one of these lectures, I had an older male explain parts of my own presentation back to me, as he sought to teach me how things really work,with the information I had provided 30 minutes before. This wasn't just him rehearsing the explanation to make sure HE understood. He was assuming that I misunderstood the basic physics of electromagnetic radiation, and was instructing me on how it really works.
This was mansplaining!
It was oddly affirmative, as it told me that he definitely saw me as a woman!