MBP 2021 M1 cannot mount my trusty WD My Book Studio II (which uses Firewire 800)

Hello! I have a WD My Book Studio II - 2 TB (2 x 1 TB) USB 2.0/FireWire 800/eSATA Desktop External Hard Drive that I bought and used up until either years ago. Kept it in cool, dust-free place. Took it out tonight. Connected it to ye olde OWC Thunderbolt II Dock, which is how I used to always use it —

1. The drive links to dock with Firewire 800
2. The dock links to the MBP 2015 with Thunderbolt 2 ports

It worked fine back then.

So now I'm doing this —

1. The drive links to dock with Firewire 800
2. The dock links to the MBP 20122 M1 with Thunderbolt 2 cable fitted with Apple's official Thunderbolt 3 (USB-C) to Thunderbolt 2 Adapter.  The drive makes noises when I connect its data cable. But it never mounts.

Does this have anything to do with how the drive is formatted?  Is the hub messing things up (but why now and not before), so that I should buy the Apple Thunderbolt to FireWire Adapter?

Running MacOS 12.5.1.

Thanks in advance.