The configuration and FW version used by the OEM needs to be reviewed in order ensure 10GbE option is enabled over a single lane.
Please extract the configuration file (.ini) file using flint tool (coming with MFT package which can be obtained from Mellanox site) or mstflint tool.
E.g.
#flint -d /dev/mst/<mst_dev> dc <file_name>.ini
Also need to extract the FW version used on the OEM ASIC - using flint query option.