Contradiction with Exodus 14:28
This verse describes how the waters returned and covered the Egyptian forces, which contradicts Exodus 8:11 where the plague is lifted and the oppressors are spared.
Exodus 14:28: And the waters returned, and covered the chariots, and the horsemen, [and] all the host of Pharaoh that came into the sea after them; there remained not so much as one of them.
Contradiction with 1 Samuel 6:9
Here God's action leads to the return of the Ark if it is His doing, opposing Exodus 8:11 where a plague is lifted, suggesting divine intervention to different ends.
1 Samuel 6:9: And see, if it goeth up by the way of his own coast to Bethshemesh, [then] he hath done us this great evil: but if not, then we shall know that [it is] not his hand [that] smote us: it [was] a chance [that] happened to us. [he: or, it]
Contradiction with Jonah 3:10
God's actions are based on repentance, removing a threat, contrasting with Exodus 8:11 where the relief from plague comes without a change from Pharaoh.
Jonah 3:10: And God saw their works, that they turned from their evil way; and God repented of the evil, that he had said that he would do unto them; and he did [it] not.