Series with: New Book, New Protagonist

[CraftyChara]

Series that follows a different protagonist in each novel.

Examples
Ghost Tracks #1
Cinder (The Lunar Chronicles, #1)
A Big Dose of Lucky (Secrets #3)
Castle in the Air Howl's Moving Castle, #2)

[Gillian]

The Twelve Kingdoms series by Fuyumi Ono. The first book is The Twelve Kingdoms: Sea of Shadow. It does eventually circle back around between protagonists.

[...cats?]

Sandry's Book (Circle of Magic series)
Black Leopard, Red Wolf (Dark Star Trilogy)
The Death of Vishnu (Hindu Gods series)
In the Woods (Dublin Murder Squad series)

[Ryan]

R.L. Stine kind of does this in his Fear Street Saga where there are individual POVs stories in each book, some skipping a generation or two.

Fear Street Sagas is a spin-off version that does a new protagonist per book since the timeline varies with each

Fear Street Seniors also does this, with selected members of a Senior class, however, some of them are given more attention in cycling than others.

[Robert]

Gideon the Ninth

[Florence]

The spinster club series by Holly bourne follows a different friend in a group in each book

[Florence]

Also the discworld series by terry pratchett has lots of mini series within it based around a huge amount of different protagonists

[Nora]

Seanan McGuire’s Every Heart a Doorway and sequels