Is there a contradiction?
God is not a man, does not change, cannot be tempted, does not sin, is not weak, needs no one, does not lie, does not change his mind, is not born and cannot die.
Numbers 23:19 God is not a man, that he should lie, Neither the son of man, that he should repent: Hath he said, and will he not do it? Or hath he spoken, and will he not make it good?
1 Samuel 15:29 "And also the Glory of Israel will not lie or have regret, for he IS not a man, that he should have regret."
Hosea 11:9 "I will not execute my burning anger; I will not again destroy Ephraim; for I am God and not a man, the Holy One in your midst, and I will not come in wrath."
Psalm 102:26 They will perish, but you remain forever; they will wear out like old clothing. You will change them like a garment and discard them.
Romans 11:29 For the gifts and the calling of God are irrevocable.
James 1:13-15 13 When tempted, no one should say, “God is tempting me.” For God cannot be tempted by evil, nor does he tempt anyone; 14 but each person is tempted when they are dragged away by their own evil desire and enticed. 15 Then, after desire has conceived, it gives birth to sin; and sin, when it is full-grown, gives birth to death.
Job 25:4-6 - 4 How then can man be justified with God? or how can he be clean that is born of a woman? 5 Behold even to the moon, and it shineth not; yea, the stars are not pure in his sight. 6 How much less man, that is a worm? and the son of man, which is a worm?
Malachi 3:6 - "For I [am] the LORD, I change not; therefore ye sons of Jacob are not consumed."
Conclusion: Either in Exodus ‘Lord’ is not referring to God or it’s a contradiction, probably manipulated for a particular opinion.
For more see Hebrew 13:8 is Jesus God - https://hermeneutics.stackexchange.com/a/77131/33268