Middle grade fiction for an 8 year old with a cliff hanger at the end of every chapter

My 8 year old loves reading, and I am constantly on the search for more books for him. He has a high reading level but his reading maturity is that of an 8 year old.

Right now he has been reading a lot of Minecraft novels (the Max Brooks series and the Diary of an 8 Bit Warrior series). He likes books that are fast paced. He also recently enjoy Last Gamer Standing, all of the Big Nate and Diary of a Wimpy Kid books. He is not ready for anything YA. He didn’t like the Wings of Fire or the Warriors series.