Critical Issue
Due to a problem with the Intel® Quartus® Prime software version 18.0 and earlier, the Low Latency Ethernet 10G MAC Intel® FPGA IP's avalon_st_rx_pfc_pause_data signal is de-asserted for only one clock cycle after receiving an XON request in PFC implementations. The avalon_st_rx_pfc_pause_data signal continues to be asserted until the pause quanta expire or become zero.
No workaround available.
This problem has been fixed starting in the Intel® Quartus® Prime Pro version 18.1.