Sitecore - 角色提供者的交换提供者不尊重域

We have multiple sites running off one instance of sitecore. One of the sites requires the users & roles to be managed through an external back end system and as such, we have configured custom membership & role providers along with domains for each site. However, for some reason the switcher on the role provider does not seem to be being respected. If I log into the CMS as sitecore user, it still calls my custom role provider to try and get roles for this user, despite the role provider being configured against a different domain?We have multiple sites running off one instance