Ephesians 4:15 NKJV but, speaking the truth in love,
“It is the tone that makes the music”(French proverb). It’s not what you say but how you say it. Sometimes words spoken, no matter how true do not have the desired impact not because of anything but the manner with which it is said. If someone is offended at your attempts to help them improve etc., check your motives. Maybe they felt judged or condescended to. Are you saying to prove you are better than them, or because you really love them? Let love be the motive.