Stumbled onto this thread a bit late.
If it's happening on a Silicon Macbook, you may want to go into your Privacy & Security Settings, scroll all the way down and change "Allow Accessories to Connect" to "Every Time"
Then disconnect and reconnect your monitor.
It's related to USB Restricted Mode on new silicon-based Macbooks. Not an issue for desktop Macs.
https://support.displaylink.com/know...cted-mode-prot