Why am I getting a handshake time out after 10000ms?

Question

I am facing this handshake timed out after 10000ms while connecting via api gateway

I am getting below error in my API gateway while connecting to one of the micro-service REST api via this gateway url.

ERROR o.s.b.a.w.r.e.AbstractErrorWebExceptionHandler - [a20cd6e8-867608]  500 Server Error for HTTP POST "/myRestEndpoint"
io.netty.handler.ssl.SslHandshakeTimeoutException: handshake timed out after 10000ms
    at io.netty.handler.ssl.SslHandler$5.run(SslHandler.java:2054)
    Suppressed: reactor.core.publisher.FluxOnAssembly$OnAssemblyException: 
Error has been observed at the following site(s):
    |_ checkpoint ⇢ org.springframework.cloud.gateway.filter.WeightCalculatorWebFilter [DefaultWebFilterChain]
    |_ checkpoint ⇢ org.springframework.boot.actuate.metrics.web.reactive.server.MetricsWebFilter [DefaultWebFilterChain]
    |_ checkpoint ⇢ HTTP POST "/myRestEndpoint" [ExceptionHandlingWebHandler]'

Could anyone please guide me here the required steps to be taken care? Thanks.