We are implementing the SSO via the Keycloak. When an user wants to access our resources on desiredUri, he is automatically redirected to the keycloak login page{keycloakServerHostname}/auth/realms/{realmName}/protocol/openid-connect/auth?response_type=code&login=true&scope=openid&state={uuidOfStateForCSRF}&client_id={clientName}&**redirect_uri**={**desiredUri**}.
Then a login form is presented, but when I fill in the credentials and the POST call submitting the request is issued on Keycloa, the response from Keycloak is 302 FOUND, but the Location header does not contain my desiredUri+paramsForGettingTokens, but consists of keycloakServerHostname+paramsForGettingTokens instead.
The weird thing is when I manually put i.e. google.com to redirect_uri param, it works and the location header points to google.com, but as soon as I put there localhost, some IP etc. (not resolvable by a public DNS), it stops working and starts to ignore the redirect uri.
It looks like the Keycloak is validating the redirect uri with some kind of DNS lookup and when it cannot resolve that DNS, it puts the baseUrl of Keycloak there instead.
How can I turn off this behavior?
My client settings are as simple as they can be: Keycloak settings screenshot
Thanks for any advice.