Strange working of Belkin USB 3.0 4-port hub F4U073 - is the power connection redundant?

New Macbook Pro 16" running MacOS Catalina 10.15.5

New Belkin USB 3.0 4-Port Hub F4U073 + USB-C Cable F4U088

I have several peripherals that won't go straight into USB-C, hence the hub.

When I plug in the power to the hub, the MacBook cannot see the files on Western Digital My Passport Ultra external drive. When I disconnect the hub power, the MacBook can see everything fine.

In other respects the hub works fine whether the power is plugged in or not - driving the printer, and an external DAC audio box and speakers.

My inclination is just to leave the hub unpowered - the Macbook is always connected to power when on my desk.

But is this as Belkin intended?