Why fc-hba show 4gb speed only for 8G fibre channel adapter after its replacement?

Issue

• Due to HBA Hardware failure , replace it with new HBA card.

$ cat lspci |grep -i fibre
0b:00.0 FibreChannel [0c04]: Emulex Corporation LPe12000 Series 8Gb Fibre Channel Adapter[10df:f100] (rev 03)<=new HBA showing 8G
84:00.0 FibreChannel [0c04]: Emulex Corporation LPe12000 Series 8Gb Fibre Channel Adapter[10df:f100] (rev 03)

• Only 4gb speed displayed from vendor script.

# ./check_fiber.sh
Path    SCSI            WWN                  State      Speed    Brand    Firmware Topology
host1   0000:0b:00.0    10000090fa402**1     Online     4 Gbit   Emulex   2.01A12  no_cmd 
                                                        ^^^^^
host2   0000:84:00.0    10000090faecc**0     Online     8 Gbit   Emulex   2.10X6   no_cmd

• Checking /sys/class/fc_host/host*/speed that the card working only at 4g.

$ grep -Hv "zz" /sys/class/fc_host/host*/speed
/sys/class/fc_host/host1/speed:4 Gbit
/sys/class/fc_host/host2/speed:8 Gbit