Force iSCSI Disconnect

Question

I've been toying around with iSCSI for a little while (FreeNAS 11.1-U5 target, Win10 Pro initiator) and have run into what would be a bit of a deal-breaking issue: I can't seem to disconnect from an iSCSI target, regardless of what I try. All methods get a "The session cannot be logged out since a device on that session is currently being used" message, and fail to disconnect.

What I've tried:

• Clicking Disconnect in the iSCSI Initiator panel
• Running the equivalent command in PowerShell
• Taking the disk offline in Disk Management first
• Disabling the Microsoft iSCSI Initiator device in Device Manager (requires a reboot, not tenable)
• Turning the iSCSI service off in FreeNAS (this works eventually, but I'd like to not have to do it this way, if I can help it)
• Per other sources, I've removed all favorite targets and target portals in the iSCSI properties dialog.

The extent is not currently initiated in Windows, and therefore does not have a file system (so, if I understand correctly, cannot be accessed by the OS in a way that would hold the connection open).

My preferred behavior would be to disconnect on request (or at least, successfully force disconnect), so I can then connect from another machine, and then back again when necessary.

Thanks in advance for any ideas!

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Hardware Details:

Win10 Pro System (desktop): Ryzen 5 1600X, 16GB RAM, NVMe boot drive, Mellanox ConnectX-2 (direct connection to server)

FreeNAS System (server): Core i3-4170, 32GB RAM, 4×10TB in RAIDZ2, Mellanox ConnectX-2 (direct connection to desktop)