I've completed all the side quests that I can find in Monquista, and I still don't have the "Chapter 3" badge. I have been searching with some help from other sites for quests that I may have missed.

Any suggestions for quests I may have missed, and where I might find them?

So far, I know I've done the following:
"Lost!" in La Mancha, given by Cristoval de Concha
"Crates and Barrels" in La Mancha, given by Damien Ramirez
"Vanquish Them!" in La Mancha, given by Pancho Stanza
"Which Came First?" in Puerto Mico, given by Brother Carlos
"Monkey Trials" in Puerto Mico, given by Brother Enrique
"The Borgia Letter" in St. Bonobo's Abbey, given by Cesare Borgia
"The Painter's Promise" in St. Bonobo's Abbey, given by Leonardo Michelangelo
"If There's a Quill, There's a Way" in St. Bonobo's Abbey, given by Luis d'Amboise
"Thirsty for Revenge" in St. Bonobo's Abbey, given by Miguel de Olivares
"In Sickness and in Health" in St. Bonobo's Abbey, given by Sebastian Conchada
"The Draught" in Zenda, given by Alfonso Flores
"Solid Proof" in Zenda, given by Prefect Lorenzo