elasticsearch – Span details not visible in trace waterfall view of Elastic Kibana APM

I use open telemetry to manually instrument my apps. I am sending traces to open telemetry collector and finally to elastic APM server. When I am at the trace waterfall view in Kibana APM, and click on a child span, I don’t see any span details. I did some comparison of raw traces in index only to find out that somehow APM server isn’t generating transaction id field for child spans. I believe this could be the reason why child span details aren’t displaying even though they exist in index. Any leads on how to resolve this?
Missing span details