I have been asked by flaviarnn to submit this issue:

We used in our code setMaxInactiveInterval() method (indirectly by using HttpSession) to dynamically switch on/off timeouts. It worked perfectly on Wildfly 19.0.0.Final (which contains undertow-core v2.0.30), but suddenly stopped working when app has been migrated to spring-boot v.2.3.2.RELEASE (with embedded undertow-core v2.1.3.Final). Unfortunately our code invokes setMaxInactiveInterval() method outside of http request/response lifecycle. My question is if it is a chance to bring back the old functionality (with bumpTimeout() into setMaxInactiveInterval() or we should implement our own http session timeout mechanism?