628X iSCSI Timeouts

I have a ReadyNAS 628X connected to a server running Windows Server 2019 that functions has a Hyper-V host and a Veeam backup server.  The devices are directly connected via two 10GbE links, with each link dedicated to its own LUN Group.  During some intensive operations, such as nightly snapshots or certain Veeam operations, the Microsoft iSCSI Initiator drops and resets the connection to both LUN Groups, logging event IDs 9, 63, 32, and 10 (but mostly 9).  The logs on the ReadyNAS show nothing.  How can I verify whether the issues lies in the Microsoft iSCSI Initiator or the NAS itself?