I changed my company's subdomain, but the new URL won't open. Why?

Configure your subdomain in Organization & Settings → Company Profile → Brand Assets → Login Page Subdomain Setting, then click Save. The system will notify the administrator to activate the URL. For the first-time setup, it takes effect immediately. For subsequent changes, a change notification is sent and the administrator must process it before it becomes active. Until then, the old URL continues to work. Subdomain rules: 1–63 characters, alphanumeric and hyphens only, no hyphens at the start or end. Must be unique across the entire system; if another company has used it, you cannot. Reserved words like api, push, invitation, www, service, g4 cannot be used. If rejected, the screen shows the message "This may be a reserved word or already in use by another company. Please try a different one."