New Relic Java recordMetric not showing custom metric data

I'm working with the New Relic Java agent and trying to record a simple custom metric using recordMetric.

My use case is very straightforward: I want to track something like "transactions per second" or any simple integer-based metric.

Here is a simplified version of what I'm doing:

public String simpleFunction() { Random ran = new Random(); NewRelic.recordMetric("Custom/TestData/RequestsPerSecond", ran.nextInt(10, 100)); return "Hi"; }

This function represents my actual implementation, just simplified.

The issue is that this does not seem to work — I don't see any custom metric data in New Relic at all.

Important context:

The New Relic agent is correctly configured.

Data is being sent successfully using other APIs:

recordCustomEvent

noticeError

I can see those in New Relic without any issues.

I've followed the naming guidelines for custom metrics (Custom/...).

However, nothing shows up for this metric.

I've also tried querying it using NRQL:

SELECT * FROM Metric WHERE metricTimesliceName LIKE 'Custom/TestData%' SELECT average(newrelic.timeslice.value) FROM Metric WHERE metricTimesliceName = 'Custom/TestData/RequestsPerSecond' SINCE 30 minutes ago TIMESERIES SELECT average(newrelic.timeslice.value) FROM Metric WHERE metricTimesliceName = 'Custom/TestData/RequestsPerSecond' SINCE 1 hour ago

I even tried browsing metrics manually, value by value, and still nothing appears.

I understand that there are built-in APM approaches to derive metrics like throughput automatically, but in this case I specifically want to record it manually using recordMetric.

Question:
Why is recordMetric not producing any visible data in New Relic, even though the agent is working correctly for other features?