Messages in iCloud Taking Up More Space than It Should

In iCloud, it says Messages is holding up 5.5 GB of space yet I’m adding up all the data the messages actually take and it’s only 600 MB. This came after I deleted many old messages in order to free up space. So now I’m wondering if iCloud just has the old messages I deleted backed up. I’ve tried restarting my iPhone if that was part of the problem but it came to no avail. Now I’m wondering what’s wrong and why it still isn’t going back to 600 MB instead of the 5.5 GB it says it has.