I believe that both titles refer to a Manifestation of God, not to God.
Jesus being the Son of God doesn't mean that Jesus is not God. Is Christianity Polytheistic?
Monotheism
The original religion of ancient mankind was monotheism, i.e., the worship of the one, true Supreme Being. This is demonstrated both by the testimony of the Bible and by a study of anthropology. (We have introduced testimony for the anthropological evidence of man’s original monotheism in our little book, Biblical Studies in the Light of Archaeology, pp. 5-6.)
Genesis 1 begins with the affirmation that “God created the heavens and the earth.” The term “God” in the Hebrew Bible is Elohim.
In his famous work, Synonyms of the Old Testament (1871), Robert Girdlestone noted that Elohim is found some 2,555 times in the Old Testament. In 2,310 of these cases the title refers to the true God, while in the remaining 245 instances the word is employed in a variety of “lower senses” (2000, 31).
Elohim is a plural term. Various explanations have been offered for this plurality. For example, some have suggested that the word is designed to reflect the plenitude of divine majesty (i.e., the vast array of sacred qualities incapable of being expressed by a term of singularity).