OIDC: different login timeout for desktop client versus web UI

This is not really an issue of the desktop clients, but a question concerning the OIDC setup and a possible knowledge gap on my side. Would be great to see hints from OIDC experts :wink:

The OIDC setup follows OpenID Connect (OIDC) :: ownCloud Documentation

The OIDC realm has a generaI re-authentication timeout of 8 hours (SSO session idle + session max) which is configured in the realm settings on the keycloak IDP. While this is intended for the web UI logins, the desktop sync clients should always start authenticated whithout requiring a new re-authentication workflow every day.

I assume I have a mis-configuration on the IDP. Any ideas whats going wrong here?