That should be done in SetSessionData.java.
I have some troubles coming from 9.24 with the "old" OIDC module (v3.3.3) upgrading to 10.18.3. Suddenly the cookies don't seem to work anymopre, resulting in going back to the login page.
Replacing the OIDC module is a "dumpy ride" with lots of refactoring in the app.
I tried to replace the SetSessionData.java from the new "Mendix" module to the app, but that didn't work. (would be nice).
I think I have to continue with removing the old OIDC and replace it with the new OIDC. But will it work then???
Somebody more experience with this?