[keycloak-user] SSO session timeout with OIDC client and SAML client?

We have a realm with two clients, one is a Java web app with OIDC, and the other is a 3rd-party app with SAML. If a user navigates to the SAML app and works there for 30 minutes or more (our realm's "SSO Session Idle" setting), then they get logged out of the OIDC app (we think because once you get in and start using the SAML app, no more authentications are requested and no refresh token requests are made). Has anyone seen this? Is our theory correct? Do you know of a fix or workaround? Thanks! Regards, Peter Boucher