Property 'session.timeout.auto.extend=false' is configured but browser still calls 'extend_session'

Issue

In portal-ext.properties the following property session.timeout.auto.extend=false is configured, however in the Network tab of the Developer Tools of the browser 'extend_session' is still being called.

Sessions are important for tracking attributes, such as attempts to log in to the portal, the locale of the user, the browser, or if the user is from a mobile device. Inter-portlet communication and portal-portlet communication also use session attributes. So whether a user is a guest or not, sessions provide important functionality to the portal.
Based on this, there was an issue in the past where this behavior was discussed: LPS-47190, and the design choice is to extend sessions that expire instead of having permanent sessions. Having sessions that expire helps to reduce the server overhead by closing inactive sessions.
If someone's goal is to reduce the calls to extend_session, it can only be done by increasing the session.timeout property's value along with the same counterpart in web.xml.