God the Father is the ultimate creator, but both John and Paul indicate that it was the pre-incarnate Jesus that performed the actual work of creation:
All things were made through Him, and without Him nothing was made that was made.
— John 1:3
For it was fitting for Him, for whom are all things and by whom are all things …
— Hebrews 2:10
… the mystery, which from the beginning of the ages has been hidden in God who created all things through Jesus Christ
— Ephesians 3:9
When Jesus says that "God created" in Mark 13:19, he is of course referring to the Father.
Generally it is the architect that gets the credit for designing a building, not the engineers for constructing it.
Isaiah 44:24 refers to YHWH as the one "who makes all things, Who stretches out the heavens all alone, Who spreads abroad the earth"
That is, it was YHWH that performed the creative work that John and Paul attribute to Jesus.
But there is no contradiction here, because before his incarnation as a human being, Jesus was YHWH, Jesus was the God of the Hebrew scriptures.
Until the human Jesus revealed the existence of the Father, the world had no idea of his existence:
… Nor does anyone know the Father except the Son, and the one to whom the Son wills to reveal Him.
— Matthew 11:27
O righteous Father! The world has not known You, but I have known You; and these have known that You sent Me.
And I have declared to them Your name, and will declare it, that the love with which You loved Me may be in them, and I in them.
— John 17:25–26
For more details, see my answer to contradiction - How can John 1:18 say that "No man has seen God" when the Bible says that Abraham, Moses, Job and others have?