Putting it here because I don’t see it in the list:

Girl Genius by Kaja and Phil Foglio

Steam punk and she does get twitterpatted about some boys but the whole story is about her making her way in the world.

Not sure if you’ve already read Discworld but the Witch series fits a lot of your requirements. Maskerade would by my first for it’s hilarity.

italian tomatoes have entered the chat and agree with their golden apples.

Well now, I’m not offended or anything, you asked a question and I’m answering it with my opinion. That’s just it, where do we draw the line? What about travel books? On the origin of species was written on the other side of the world in a time where that kind of travel was crazy dangerous. is that an isekai? What about Woman marrying against her will and going to another city far enough away she know no one or anything and especially not the local customers? What about Rabbit the great and powerful? He travels from one kingdom rules by necromancers to a world where magic itself is different. is that enough travel? Your question is valid. The answer is no, not because you asked a bad question but because the more you stretch the definition the less it means anything. Pride and prejudice isn’t an isekai. If you broaden isekai to cover it than you just made it into the word: Book.

I’d ask first and foremost WHAT did you like about it and which part. Leaving my personal crazy theories out There is a HUGE tonal shift at the end of book 4. Did you like it more before that? After that? Did you like the magic? Did you prefer the sorta mysteries?

Did you love reading about those people growing and changing?

Personally i cannot recommend enough Superpowereds by Drew Hayes. 4 books and a few side stories, set in college and has that adventure and fantasy feel with a serious mystery woven through the whole series.

BUT i pretty much have never reread any of the HP books after 4 once the 7th came out.

If you liked the later books and the coming of age than Yes, Percy Jackson, the first few books at least capture a lot of that grim dark coming of age in a world that was messed up by the previous generation.

I would also recommend the Books of magic. The novels have no mystery but they “inspired” HP a lot.

The first is just multiverse fantasy and not an isekai amd the second is a time travel story that has its own subgenres like “Connecticut yankee in king Arthur’s court” and are not isekai either. You’re over broadening a term and loosing it’s meaning.

“It was a Unicorn in the same way nanny Ogg was a Unident.”