I'm using spring-boot-starter-webflux lib, and I'm also facing the following SSLEngine issue with negligible load. https://github.com/reactor/reactor-netty/issues/2509
After dinning, I found that the reactor-netty used by spring-boot-starter-webflux(from 2.7.X to 3.4.0) is always 1.0.20, it didn't cover the important change in https://github.com/reactor/reactor-netty/pull/2518 which released in reactor-netty 1.0.24. Can you upgrade reactor-netty to 1.0.24 or higher??
Comment From: wilkinsona
Spring Boot imports Reactor's bom to manage the version of Reactor Netty. In the latest Spring Boot 3.3.x release, the version of reactor-netty that comes from Reactor's bom is 1.1.24. In Spring Boot 3.4.0, it's 1.2.0.
If you're seeing 1.0.20 then something else is downgrading the version of reactor-netty. If you need some help determining what that is, please post a question on Stack Overflow with a complete build.gradle or pom.xml that reproduces the problem.