Remember that we are just users like yourself. I have only the information your provide (and by implication, do not provide) to go by. Frankly I wasn't sure to which "profile" you were referring. Maybe the artist's own web page?
It is possible the entry has been re-listed. Your playlist may point to the old listing but the artist's profile points to the current one. People in the past have complained about not being able to redownload tracks they purchased years ago and still see on the site. Likely the track was replaced with a remastered version and isn't the same.
If you really think something is messed up on the web site, report it to Apple. Refer to this page for Apple Support features ➔ Contact - Official Apple Support
Select from the presented options until you find a solution for your issue, or see if there is a chat or phone call contact method offered lower on the page (you sometimes have to narrow down the options multiple times before this is shown). If you do not see your issue, keep experimenting with any series of selections until you reach one that offers a chat session or a telephone call and get the representative to redirect you.
This page has telephone numbers for contacting Apple for support and service ➔ Contact Apple for support and service - Apple Support
