The curious case of copyright

I don’t have any idea how copyright works online. As a consumer, you might think using other people’s content without their permission is an infringement of copyright law. Then again there’s the issue of fair use. As a content creator, you never know what’s going to get claimed.
Today I was editing this video of a drone shot in Beppu city. I wanted to add a small composition from Chopin. I got introduced to his compositions through my Japanese grandma. She wanted me to play his music while we were on a drive. So I wanted use a short part for my video.
I thought his music is open to the public domain. “Frédéric Chopin passed away more than 160 years ago -- sufficiently long ago that today all of his compositions belong to the public domain.”- that’s what I read on google. I make my video and upload it on Facebook. After a few minutes, I hear that some company claimed that it was a copyright infringement and some countries will have the audio muted. It made no sense to me. I did a little more googling and found out that although his music is public domain some recordings are copyright protected. Which still makes no sense to me.
While my issue is a minor issue, many big creators face a lot of copyright issues. I hope someday we can find a logical solution for the situation.