1. Check whether the latest updates to the project have been made in the subsite and the changes are reflected in the subsite.
2. Check if the appropriate permissions have been assigned for users to have access to the custom view.
3. Ensure that the custom view has been configured properly.
4. Clear the browser cache and restart the browser to check if the changes are reflected in the custom view.
5. Check with the site admin if all settings are properly configured.
6. Check if the app restart is needed as it may resolve the issue.