It happened at the time of Solomon's old age that his wives guided his heart after other gods, and his heart was not fully with Yahweh his God as the heart of David his father [had been].

then you shall hear in heaven the place of your dwelling, and you shall forgive and act and give to the man whose heart you know, according to all his ways, for you alone know the heart of all the sons of man.

He walked in all the sins of his father that he had done before him, and his heart was not fully with Yahweh his God as the heart of David his father.