Thank you for reaching out to Okta. The "Prompt for re-authentication" option applies when the user clicks on the application chiclet from the Okta Dashboard or when the user tries to access it from the login page. If the user is already on the application page, access to resources within will still be granted without re-authentication. The "Session lifetime" configured under the Okta Security>>Authentication>>Sign-on, apply to the Okta session. The timeout for a JAMF will have to be set on the app side if it supports customisable session times. I recomend reaching out to their support as well.