Issue with Schema in Text Area (CKANext-Validation)

## CKAN version 2.9

## Describe the bug
I'm using ckanext-validation for data validation. Uploading a schema via file or URL works, but manually entering it in the text area doesn’t attach the schema to the resource. Validation options are applied correctly, but the schema is missing.
Has anyone encountered this or know a solution?

Reproduce the issue in CKAN 2.9 with ckanext-validation by comparing schema entry through the text area against file or URL upload. Trace how the manually entered schema is attached to the resource and verify that validation options still work. Done means a schema entered in the text area is attached and used for validation.

Written by the indexing model from the issue text.