The "UFO" was close enough to get everyone's attention but far enough way to not be a danger. No one knows what, or how big it was.
https://nypost.com/2021/04/25/spacex-craft-close-call-with-ufo-after-launching-into-orbit/
https://nypost.com/2021/04/25/spacex-craft-close-call-with-ufo-after-launching-into-orbit/
New York Post
SpaceX craft had close call with UFO after launching into orbit
SpaceX's Crew Dragon Endeavor spacecraft had a close call with an unidentified object before reaching the ISS. US Space Command warned the crew of a possible collision after launching into orbit.