Private Relay cannot resolve DNS lookups when connected to CalDigit Dock ethernet

(Finally) took delivery of my 16" M1 Max MacBook Pro this weekend, and after popping in my existing dock setup, replacing a work-provided 2018 13" MacBook Pro, I am unable to access the internet through the Dock's ethernet if iCloud Private Relay is turned on. Safari and other Apple apps will hang attempting a DNS resolution (Microsoft Edge, for example, is unaffected).

Disabling the interface, and using Wi-Fi, fixes the issue. As does disabling iCloud Private Relay in System Preferences — and will actually cause the loading Safari page to spring to life.

Previous MacBook Pro had no such issue in the same setup and configuration.

Also worth noted that I don't actually use Private Relay at home, but like to have it enabled when working away from Home. I actually have "Limit IP Tracking" disabled for my home Wi-Fi network and the Dock ethernet interface (as well as the appropriate hostnames of the iCloud relay servers blocked [NXDOMAIN] on my Home network) — and even still, with Private Relay enabled, the MBP won't do anything.

Disabled globally for now, but a weird glitch of the "beta" Private Relay that seems limited to the external ethernet interface of this new MBP.

Anyone else encountered this issue?