I don't think it's losing focus, quite the contrary. There's a huge focus on Gojou's development, and it's definitely leading to a point where Gojou will eventually think himself worthy of Marin. His perceived-worthiness definitely increased since chapter 1, but there's still a huge step to be taken there and this arc is, in my personal view, probably the best way to increase his self-confidence (it'll top the School Festival arc I think). Let's be patient, let Fukuda-san cook, she's definitely going to offer us a beautiful moment soon.