If Jesus is Jehovah then why did he refer to the Father as his "God"? Why are there scriptures that refer to the "God" of Jesus?
Christ referred to the Father as his God, because (after the incarnation) Jesus
was (in addition to being divine) also fully human- and all humans are to honor
the Father as their God. As Paul G. Weathers Contend for the faith (page.
“Since Christ came as man, and since one of the proper duties of man is to
worship, pray to, and adore [God], it was perfectly proper for Jesus to call
the Father “my God” and to address him in prayer. Positionally speaking as a
man, as a Jew, and as our high priest (“made like his brothers in every way,”
Heb. 2:17), Jesus could address the Father as “God.”
"Although Jesus existed from eternity past as God (Micah 5:2, John 1:1, Heb. 1:10, 7:3, 13:8, Rev. 1:17, 2:8, 22:12-13), the Father is never referred to as the “God” of Jesus except in prophetic verses referring to the coming of Christ as a man and as our high priest (Rev. 3:12).”
Christ is both God and man.