Contradiction with 1 Kings 15:14
While 2 Kings 18:3 states that King Hezekiah did right like David, this verse reveals that high places weren't removed during King Asa's reign, despite his heart being perfect with the Lord.
1 Kings 15:14: But the high places were not removed: nevertheless Asa's heart was perfect with the LORD all his days.
Contradiction with 2 Kings 16:2-4
These verses describe Ahaz, Hezekiah's father, as engaging in pagan practices, which contradicts the idea of his lineage consistently doing right as per 2 Kings 18:3.
2 Kings 16:2-4: Twenty years old [was] Ahaz when he began to reign, and reigned sixteen years in Jerusalem, and did not [that which was] right in the sight of the LORD his God, like David his father.
Contradiction with 2 Kings 20:13
Hezekiah showed the Babylonian envoys all his treasures, which later led to the Babylonian exile, showing a lack of wisdom contrary to doing right.
2 Kings 20:13: And Hezekiah hearkened unto them, and shewed them all the house of his precious things, the silver, and the gold, and the spices, and the precious ointment, and [all] the house of his armour, and all that was found in his treasures: there was nothing in his house, nor in all his dominion, that Hezekiah shewed them not. [precious things: or, spicery] [armour: or, jewels: Heb. vessels]
Contradiction with 2 Kings 21:2
Manasseh, Hezekiah's son, did evil in the Lord's sight, a stark contrast to Hezekiah's righteousness in 2 Kings 18:3.
2 Kings 21:2: And he did [that which was] evil in the sight of the LORD, after the abominations of the heathen, whom the LORD cast out before the children of Israel.
Contradiction with 2 Chronicles 32:25
Hezekiah's heart was lifted up in pride, which led to wrath upon him and Judah, contrasting with the assessment of his right actions.
2 Chronicles 32:25: But Hezekiah rendered not again according to the benefit [done] unto him; for his heart was lifted up: therefore there was wrath upon him, and upon Judah and Jerusalem.