"From what I´ve learned teaching English, and what I´ve seen in most books, the difference is that we use WHAT ABOUT + noun, and HOW ABOUT + verb. It´s a pretty simple explanation, but that´s how it´s being taught in schools in Brazil."
I disagree. Unfortunately that's a misleading explanation. See what Merriam-Webster and other reliabe sources say:
What about [=how about] coming with us?
What about driving to the coast for the weekend?
We'll need to talk about this again. What about (meeting) next week?
What about another game? [=would you like to play another game?]
What about having another drink?
How about a break?
How about going for a meal?
How about we go for a meal?
We'll need to talk about this again. How about (meeting) next month?
How about [=what about] driving to the coast for the weekend?
How about another game? [=would you like to play another game?]
What should we do tonight? How about (seeing) a movie?
How's about some more pie?
How about a cup of tea?
Hope it helps,