SpringBoot WebSocket closes ocasionally with Unexpected Status of SSLEngineResult after an unwrap() operation

Spring seems to be ocasionally closing a websocket client connection with this CloseStatus Closed: CloseStatus[code=1006, reason=Unexpected Status of SSLEngineResult after an unwrap() operation]

This happened after the connection had been active and working fine for about an hour. Here's the dependency in my pom

<dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-websocket</artifactId>
        <version>3.1.2</version>
</dependency>

Comment From: wilkinsona

Thanks for the report. Unfortunately, it doesn't include enough information for us to be able to help you.

You've said that you believe it's Spring that's closing the connection. How have you determined this? How do you know that it isn't the server-side that initiated the close?

You also said that the connection had been active and working fine for about an hour. When was the connection last active? If no data is sent for longer than a configured timeout period, the connection may have been closed. This Q&A on Stack Overflow is worth reading.