It’s by design. WordPress multi-site has superadmin, for which WordPress does not check any user capability at all. URE does not add any capability to single site ‘administrator’ role for this reason.
You can go to “Network admin->Users->User Role Editor”, select “Administrator” role, add ‘create_%’ capabilities to it, save changes. It was made for the main site. Then click ‘Update Network’. This way all roles from main site will be replicated to all other subsite.
You can replicate only administrator role to other subsites – if open URE directly from the main site, select “Administrator” role, turn ON the “Apply to All sites” checkbox then click “Update”.
