Zeniff notes that he made a covenant with the Lamanite king in order to possess the land of Lehi-Nephi (Mosiah 9:6). One has to wonder if this covenant was the reason why Zeniff's people apparently did not try to communicate with the people in the land of Zarahemla? Perhaps Laman made Zeniff promise to have no contact with the people in the land of Zarahemla. [Alan C. Miner, Personal Notes]
“Lehi-Nephi”
The name Lehi-Nephi is mentioned only seven times in the Book of Mormon, and all seven references refer to a place within the confines of a larger land of Nephi. (Allen, Exploring, p. 363) Perhaps the returning Nephites wanted to distinguish their city (Lehi-Nephi) from the general land of Nephi, which by this time was Lamanite territory (perhaps called Lehi-Laman?). The fact that Zeniff had to rebuild the walls of the city suggests that the city was, if not abandoned, at least neglected, and that the departure of Mosiah1 had not been a pleasant one.
One note of interest is that "Lehi-Nephi" might have been not only the full name of Nephi, but also the royal pedigree line by which Zeniff derived his power and protection. We see the same thing possibly happening in the future with the Lamanites who were converted by the sons of Mosiah2. For possible protection, these converted Lamanites took upon them the name of the son of the Lamanite king who was the brother of Lamoni. His name was Anti-Nephi-Lehi (Alma 23:17, 24:5), and the converted Lamanites called themselves "Anti-Nephi-Lehies."
Understanding of the term Lehi-Nephi is complicated by the use at this same time of the phrase "city of Nephi" to possibly refer to the same location. [See Mosiah 9:14-15, 20:3, 21:1, 12, 23:11.] The phrase "city of Nephi" is also used later in Alma 47:20 and describes the "chief city" of the land of Nephi (which was controlled by the Lamanites). [Alan C. Miner, Personal Notes]