trace_id and java_span_id are not showing in the Java instrumentation example

When deploying the [jaeger example](https://github.com/grafana/pyroscope/tree/next/examples/tracing/jaeger), I'm seeing two issues:
1. when checking Loki log {compose_service="ap-south-java"} , there are many errors saying "Failed to export spans. The request could not be executed. Full error message: Failed to connect to localhost/127.0.0.1:14250"
2. log of {compose_service="eu-north-java-instrumentation"} is showing the trace_id and java_span_id as empty, for example, "2023-08-09 13:43:59 | 2023-08-09 05:43:59.726 INFO [ trace_id= java_span_id= ] 1 --- [nio-5000-exec-4] rideshare.OrderService"

any idea what might be the cause?