New page error are not cleared on close

Reproduction steps

1. Create a page A
2. From the new page form, create the same page A again
3. an error is displayed, explaining that the page already exists
4. close the modal
5. click on new page again

   Expected

The form is empty

Actual

The error is still displayed.
Note that if a value was filled in the name before closing the modal, it is correctly cleared.