Due to a problem in the Intel® Quartus® Prime Pro Edition Software version 21.2 and earlier, you may see a data slip on the output path of up to 800 cycles when the PHY Lite for Parallel Interfaces Intel FPGA IP VCO frequency is around 1066 MHz, (i.e., interface frequency around 266MHz, 533MHz or 1066MHz). This problem only affects Intel Agilex® 7 FPGA devices and is PVT-dependent, which may occur even after successful hardware testing.
A patch is being created to fix this problem in the Intel® Quartus® Prime Pro Edition Software version 21.2
This problem is fixed starting with the Intel® Quartus® Prime Pro Edition Software version 21.3.