Hello jgregory419,   I could recommend checking for update after November. Dell engineering is aware of this issue and Intel plans to fix this issue at Nov Block FW.    
I have a couple of servers that are not able to update the NIC firmware on.   It gets about 30 seconds in and reboots with the following error in the lifecycle log: Unable to update the firmware of the component Intel(R) Ethernet X520 10GbE Dual Port KX4-KR Mezz to version 20.5.15 because the update operation was abruptly stopped. The reason for abrupt stoppage: Error preserving device configuration data. I have tried a few different ways of updating, through the lifecycle controller - both through the online repo as well as local file, boot to DUP ISO.  I've tried a few different versions of firmware as well.   Tried draining power and reseating the NIC adapters...Short of replacing the NICs, I'm not sure what else to try.   Please help. Thank you,
M640 blade with x520 NIC adapters not updating.