The printer’s manuscript has the plural noun form sufferings, which the 1830 typesetter interpreted as an error for the present participle suffering. His emendation is undoubtedly correct. For this verse, we have a sequence of four present participial forms: walking, teaching, suffering, and being persecuted. The probable source for the plural s in sufferings is the immediately preceding plural things (“teaching the word of God in all things”). The following plural afflictions may have also had some influence in causing the error.
Summary: Accept in Mosiah 26:38 the 1830 typesetter’s emendation of sufferings to suffering; the reading in 𝓟 is obviously wrong.