When using Splunk Observability with the Boutique EKS website, I set up a graph to show data from metric 'spans.duration.ns.p90', sf_service 'checkoutservice', and sf_operation '/grpc.health.v1.Health/Check'. With the time range set at 1 hour, I can observe a particular peak value at 2.2 million. If I change the time range to 2 hours, this same peak value becomes 4.4 million. Why is this data changing?