The current RLDS text has the singular dissension in Alma 53:9 (first introduced in the 1874 RLDS edition). But the previous verse shows that the plural dissensions is a consistent reading for this passage: “on account of some intrigue amongst the Nephites which caused dissensions amongst them” (Alma 53:8). Notice also the use of the word intrigue in both verses. The 1874 RLDS change is undoubtedly a typo since the plural dissensions in the previous verse was left alone. In verse 9, the conjoining of the singular intrigue may have prompted the replacement of the plural dissensions with the singular dissension.
Summary: Maintain both occurrences of the plural dissensions in Alma 53:8–9, the reading of the earliest textual sources, including 𝓞.