I created a YouTube channel and put a channel description. I wanted to change my channel description, so I did. Though, when I searched my channel on YouTube, I can only see the past description...how do I correct this problem?

It's likely that the new description hasn't updated as soon as you expected it to.

After changing your description, did you subsequently check the new version through searching? You may need to give it some time to adjust to the new description. Maybe check later that day or the next day.