People complaining about Yamada's insecurities being a recurrent theme, if you cant stand it I recomend reading something trash-bin tier like Citrus were every problem is magically fixed by someone screaming loudly. (Im just joking)
Insecurities ARE a recurrent problem, thats the whole point, it's not something that goes away on whim, it's something you work over time and little by little by improving yourself. Yamada is much better now than she was in the prequel, she now understands and admits she has friquent bouts of jealously, knows that it is not a good thing and doesnt want to feel this way for the rest of her life. She is even more open and honest about how she feels now, at the end of the mixer chapter, she clearly tells Kaze she was jealous of her roommate.
The problem in this chapter is that Kaze doesnt talk to Yamada about her future goals, she just told her the other chapter that her goal was to live with her the next year, while in reality she actually was pondering what to do in the future, so why no tell her? Fukami just hits Yamada with a passive-agressive blow out of nowhere, and in this chapter, for the first time (I think), Yamada is able to overcome her gloom on her own, so thats progress.