Fresco says cloud is full but all my files amount to less than 1gb

I’m using the free version of Fresco on my ipad pro 13 inch. I’m supposed to have 5gb storage and it said my storage was full, but after cleaning up I found out that all my remaining files only amounted to less than 1gb and the cloud still says I’ve used up 4.7gb.

So where’s the other 4gb coming from?

Things I’ve tried that didn’t work:

• Deleting brushes. Barely cleared up any kind of storage
• Signing out then back into my account
• Permanently deleting files on the cloud storage website

I hope someone helps solve my problem soon. I’m a teacher and I use this app to teach students so it’s an important issue to me.