Fresco says cloud storage is full but my files are less than 1gb

I’m using free Fresco on my ipad pro 13 inch. I’m supposed to have 5gb cloud storage. I recently got told it was full but after some cleaning up, I realised the rest of my remaining files only amounted to less than 1gb storage. Still, Fresco says I’m using 4.7gb storage.

So where is the other 4gb coming from?

Things I tried that didn’t work:

• Deleting brushes
• Permanently deleting files on the cloud storage website
• Signing out then back into my account

Hopefully someone solves my issue soon. I’m an art teacher and use this app to teach students due to its features and accessibility, so it’s kind of an important issue.