PIA session kickout Issue for HCM 9.1, ELM 9.1, Portal 9.1 on Peopletools 8.55.27 having SSO enabled

Hi All,

We have HCM, ELM & Portal 9.1 on PT 8.55.27 where SSO is configured. I recently upgraded the peopletools from 8.50.22 to 8.55.27. We are facing session kick-out issues when logging into Portal or HCM, whereas ELM works better. There is no Load Balancer as of now.

ISSUE :-

On first login to Portal the pagelets in the landing page are not loading properly and navigating to any page is kicking out from the session. Now, when we login again it works properly until few navigation and then kicks out. Tried to see App server & web server logs but could not find anything relevant. This is happening in all browsers, IE, Chrome, Firefox. IE better than others.