The conclusion to the story of Ammon and Lamoni has them return together. While Ammon was willing to continue as a servant, Lamoni elevated his position. The Nephite church was established. The fact that a church was established suggests that the conversion was not universal. The function of the church among the Nephites was to establish a separation of religious belief, allowing for at least two different beliefs in the same city. That appears to be what happens here as well. Many are converted. Some number are not. Churches allowed for both types of religious believers to exist in the same community.
There is no chapter break at this point. This part of the story is the setup to the story of Aaron and Lamoni’s father. That story begins in earnest in the next modern chapter, but it was part of the same chapter in 1830.