Your drawings are likely recoverable using Apple's recovery service. This issue is typically caused by a problem with iCloud itself.
Check the iOS Files App
Before using the recovery service, confirm the files are actually missing from the app's source folder:
Open the iOS Files app on your device.
Navigate to iCloud > Concepts.
Check if your folders and drawings are listed there.
Use the iCloud File Recovery Service
If your folders and drawings are missing from the Files app, you can attempt recovery:
Go to Apple's recovery service at https://icloud.com/recovery
Sign in with your Apple ID.
Follow the on-screen instructions to check for and restore any missing files.
If you are still unable to locate your drawings, please contact our support team for further assistance.