I still need to read the Harry Potter books. The second Eragon book admittedly threw me off too - I get really irritable with books that don’t set on one protagonist and instead jump around between sometimes up to 10 different characters. No, I don’t care about this new character you’ve written. Yes, I’ll happily skip -every chapter involving them-, even if it ruins the book.
If it starts out with that in mind, fine I guess, but it really bugs me when series I’ve gotten hugely invested in do that.