Getting [io.netty.handler.ssl.SslClosedEngineException: SSLEngine closed already] for HTTP/2.0 with TLS on netty

Question

I am getting below error for almost 1% of my total requests under high load e.g. 1k-2k/s requests.

ERROR org.springframework.web.server.adapter.HttpWebHandlerAdapter - [9899f030-1528794]
Error [io.netty.handler.ssl.SslClosedEngineException: SSLEngine closed already]
 for HTTP GET "/mgmt/metadata/location", but ServerHttpResponse already committed (200 OK)

Its a spring cloud-gateway application using reactor, netty with TLS and HTTP/2.0 protocol.

We tried tuning the app.httpclient.pool.max-idle-time property with 55 sec, 15 sec, 1 sec but still we see some requests failing with above error.