Contradiction with 1 Kings 9:21-22
It suggests that Solomon did not use Israelites as forced labor, which differs from 2 Chronicles 8:15 where there is more emphasis on following David's commandments, implying possible forced labor by Israelites.
1 Kings 9:21-22: Their children that were left after them in the land, whom the children of Israel also were not able utterly to destroy, upon those did Solomon levy a tribute of bondservice unto this day.
Contradiction with 2 Chronicles 2:17-18
This states that Solomon used foreigners for forced labor, which seems to contradict 2 Chronicles 8:15 by implying that Israelite rituals or duties weren't interrupted, potentially including labor issues.
2 Chronicles 2:17-18: And Solomon numbered all the strangers that [were] in the land of Israel, after the numbering wherewith David his father had numbered them; and they were found an hundred and fifty thousand and three thousand and six hundred. [the strangers: Heb. the men the strangers]