Redis session has no expiration set on high load

[verve111]

Describe the bug
Redis sessions with no expiration time are created even if the ReactiveRedisSessionRepository.setDefaultMaxInactiveInterval(Duration) is set. This happens when the app is high loaded

To Reproduce
Let's load the app using JMeter with 75 threads/users. Each request invokes the endpoint that creates a new session using session.changeSessionId(). About 10 minutes later we should notice that among sessions with ttl set, there is a few sessions with no ttl appear

Expected behavior
If ReactiveRedisSessionRepository.setDefaultMaxInactiveInterval(Duration) then all created sessions should have ttl set, even on high loads