When using the Intel® Stratix® 10 EMIF IP in a DDR4 Ping Pong PHY configuration, there is a problem with the auto-generated example design if the Efficiency Monitor is enabled.
The Ping Pong PHY calibrates successfully, and the traffic generator test passes on the ping PHY but fails with read data errors on the pong PHY. This behaviour is seen in both simulation and hardware operation.
Set the DDR4 IP parameter Diagnostics > Enable Efficiency Monitor to Disabled.
This problem is scheduled to be fixed in a future release of the Intel® Quartus® Prime Pro Edition software.