Due to a problem in the Quartus® Prime Pro Edition Software version 23.4, the F-Tile Low Latency Ethernet 10G MAC FPGA IP Design Example for the variant 10M/100M/1G/2.5G/5G/10G (USXGMII) Ethernet with IEEE 1588v2 enabled, the Synopsys VCS* simulator shows packet loss on the RX datapath due to internal path failures, this is due to the RX datapath FIFO overflow.
There is no workaround to this problem in 23.4.
This problem is scheduled to be fixed in the future release of the Quartus® Prime Pro Edition Software.