I have contacted support who have told me to place both NICs on different subnets.
So I put one on 10.1.1.254/24 and one on 10.2.1.253/24 for testing, and now iSCSI multipathing works consistently all the time and both adapters show I/O.
They stated that the linux system which their firmware is based off will choose which adapter to use based on the routing system so if 2 NICs are on one subnet, and the only workaround at this time is to use different subnets.
