The Utilization Average and Utilization In have the same value.
When running Trend reports for As-Polled data against Interface Utilization In, Out and Average metrics, the Trend line for Utilization In or Out is matching the Average Trend line.
This is validated via CSV exports showing the metrics with the matching Trend lines have matching poll data samples.
This can also be seen by right clicking on the duplicated Trend line to Hide/Focus one Metrics Trend line vs another.
The same happens to the 95th Percentile version of the Utilization Metric.
This is seen for Interfaces that support the High Speed Vendor Certification.
The reason Utilization In or Out, and Utilization Average, are the same has to do with the duplex value for the interface involved.
The High Speed Vendor Certification is set up to take the maximum value of In or Out Octects and Calculate Utilization if dot3StatsDuplexStatus is set to value 3.
If the value is 1 or 2, we sum the In and Out values. This is where we see it in the High Speed Vendor Certification:
All supported Performance Management releases
This is functioning by design if the described behavior in the Cause section above aligns with the interfaces configured dot3StatsDuplexStatus value.
What is the dot3StatsDuplexStatus for the interface at issue? Can determine by using an SNMP query tool to look for the interfaces value for the dot3StatsDuplexStatus OID 188.8.131.52.184.108.40.206.2.1.19.
An alternative method to expose that value is via Detailed Poll Logging and/or Detailed SNMP Logging via the DA:8581/dcdebug page. Both will show the regular polling of that OID for polled interfaces and expose the value per interface index.
If the value of the dot3StatsDuplexStatus setting for the interface doesn't align with expected results, please open a support case for further investigation.