Create a doctype without check field "Custom" do now show in menu

ERPNext: v12.6.0 (version-12)
Frappe Framework: v12.4.1 (version-12)
Custom App: v0.0.1

I create create a new doctype under module “Website”, however, it is not showing in #modules/Website even i edit the config/website.py, if I uncheck field “Custom”, it can show under “Setup” or “Document” depend on the value I select in View setting, anyone can help?