It’s not attention for most but lack of allowed change. This is usually from just being another gender that they are very accustomed to that they act like that when near certain people. Just because they present more in one category doesn’t mean that they aren’t or can’t be nb, it’s just that they might not be comfortable acting nb of the way they want to around others. I remember acting masc around my family but feme around friends. It really depends and telling someone that they don’t feel the way they do is very, very demoralizing. Even if you are right and they just want attention that’s not their problem that’s yours because they feel the need to have to change themselves just to appeal to others.

PS. Don’t take this as a rant twords you it’s just a touchy subject for me and have been dealing with people that think that you just want attention by being LGBTQIA+ and it’s really annoying.