Most of the time the cause of this is because the song mp3 needs to be remuxed and replaced. You can do this using an audio editing software (i use audacity: https://www.audacityteam.org/). Drag the mp3 inside when you open the program and export it without making any changes to the audio. Then drag it into the beatmap folder and delete the original audio (make sure you set the new audio to audio.mp3). This should fix the issue.
you might want to wait. when you update preview points/mp3 files it's only natural for the website to take at the very least a few hours before updating