Contradiction with Matthew 13:11
Acts 20:27 speaks to declaring the whole counsel of God, while Matthew 13:11 indicates knowledge of the mysteries of the kingdom is given to some and not others.
Matthew 13:11: He answered and said unto them, Because it is given unto you to know the mysteries of the kingdom of heaven, but to them it is not given.
Contradiction with Luke 8:10
Acts 20:27 involves openly declaring counsel, whereas Luke 8:10 suggests parables are used to conceal meanings from some.
Luke 8:10: And he said, Unto you it is given to know the mysteries of the kingdom of God: but to others in parables; that seeing they might not see, and hearing they might not understand.
Contradiction with 1 Corinthians 2:7
Acts 20:27 is about declaring all things, but 1 Corinthians 2:7 talks about wisdom of God in a mystery, hidden from others.
1 Corinthians 2:7: But we speak the wisdom of God in a mystery, [even] the hidden [wisdom], which God ordained before the world unto our glory:
Contradiction with John 16:12
Acts 20:27's declaration of all counsel contrasts with Jesus withholding certain teachings because the disciples were not ready for them.
John 16:12: I have yet many things to say unto you, but ye cannot bear them now.
Contradiction with Romans 11:33
Acts 20:27 involves declaring God’s counsel, while Romans 11:33 describes God’s judgments as unsearchable and his ways past finding out.
Romans 11:33: O the depth of the riches both of the wisdom and knowledge of God! how unsearchable [are] his judgments, and his ways past finding out!
Paradox #1
Some people might see a conflict in striving to share all teachings equally when some teachings can be difficult or uncomfortable for others to hear or accept. It may feel inconsistent to be fully open when trying to be sensitive to different beliefs and contexts.