What loader did you use? Did you build with ./my.sh RS4021xs+ ? In the case of Broadwell nk platforms such as RS4021xs+, the m shell has a process to avoid conflicts between the igbxe driver and the built-in vanilla igbxe driver.   E10G21-F2 is the same as the OEM version of X710-DA2. The linux extension driver of X710-DA2 uses i40e. With the already built-in i40e's vanilla driver included If the TCRP duplicates the auto-discovered i40e, a conflict is expected.