To me the "I don't like girls, I just happen to like [name] because she is [name]" trope is just a big red flag that the writer is approaching the story from the angle of yuri as a romantic fantasy rather than homosexuality as a reality.
It's not that they're necessarily trying to be homophobic, but...
There's no need for a "but".
Indifference towards the gender of your own or someone else's love interest used to be an ideal, an aspiration. It certainly doesn't represent societal reality at large, but I still see it as an ideal. If you're in a monogamous relationship, you're effectively "monosexual" anyway.
That would imply that your sexuality only exists when you're acting upon it. You can still find other people attractive in a healthy, stable, monogamous relationship.
Anyway, this manga has really fallen for me, which is unfortunate. It was getting translated around the same time as "Our Yuri Started With Me Getting Rejected in a Dream", but the difference in execution feels much better in that one, not because anything has happened in that one either, but at least we get both people's perspectives like someone else said. I still have no clue what Yuzu's deal is. And it's weird because this manga started out with Yuzu being confessed to. It would be easy enough for someone, anyone, to start a conversation with Yuzu about what if anything she's feeling. I don't know, I'll keep reading this till the end probably, but I don't look forward to it in the same way anymore.