Due to a problem in the Quartus® Prime Pro Edition Software version 24.2 and earlier, the Low Latency Ethernet 10G MAC IP with IEEE 1588v2 feature may perform checksum correct insertion to the packet when a user does not assert the checksum correct control signal if the previous packet has checksum correct insertion due to the IP's behavior.
To work around this problem, force the IP input signal "tx_etstamp_ins_ctrl_offset_checksum_correction" to 16h'0000 in the RTL when checksum correction is not requested for the particular packet.