Scribe 2 of 𝓟 initially wrote “in the land of Zarahemla” after churches in verse 22. But this was an error due to his eye accidentally moving down to the next line in the original manuscript, where it read “seven churches in the land of Zarahemla” (verse 23). There would have been almost exactly one entire line of 𝓞 between the two instances of churches that led to this initial copying error:
It appears that virtually immediately scribe 2 of 𝓟 caught his error and crossed out this addition to the text (there is no change in the level of ink flow for the crossout).
Summary: Accept in Mosiah 25:22 scribe 2’s crossout of the extra “in the land of Zarahemla” in 𝓟; the source for these words was in the next line of the original manuscript.