Unable to register / scan a site with WP Toolkit

Symptoms

Using WP Toolkit, you are not able to register an existing site. The interface will display one of the following errors:

CPANEL_ERROR: Integrity constraint violation: 19 FOREIGN KEY constraint failed, 
query was: INSERT INTO "InstanceProperties" ("instanceId", "name", "value") 
VALUES (?, ?, ?)

CPANEL_ERROR: Unable to write content to a file. 
An error occurred during the creation of a temporary file: open 
/home/$cPanel_user/.temp.1747652765991824294..wp-toolkit-identifier: 
permission denied in /usr/local/cpanel/3rdparty/wp-toolkit/plib/library
/Application/Cpanel/Panopticon/LocalCpanelPanopticonExecutor.php:181

CPANEL_ERROR: ERROR Failed to check user fields of user 
'$cPanel_user', user will be removed and created from scratch: 
PleskExt\WpToolkit\Exception\Cpanel\UserIdentityFieldsMismatch: Stored 
information about user are differs from actual in 
/usr/local/cpanel/3rdparty/wp-toolkit/plib/library/Service/Cpanel/User/
CpanelUserHelper.php:227

CPANEL_ERROR: Scanning for WordPress websites finished with errors:
Task is not responding
Scanning for WordPress websites finished with errors:
Task is not responding

Cause

The home directory permissions are incorrect, and should be verified and changed to the required values.

Resolution

Verify the permission of your home directory and make sure they are set to the correct permissions.

What are the default file permissions for public_html?