OEMR XL R740 2.18.1 - how to roll back bios

Hi Dell team,

Could you please advise if we good to rollback or downgrade the bios ?

reason because after the upgrade to bios 2.18.1 on OEMR XL R740 and the port went down.

Card details is Mellanox ConnectX-5 2x25G (MCX512A-ACAT)