About 1 times out of 4, USB devices don’t work when docking my M1 Macbook Air. Unplugging the USB-C cable and plugging back in again once almost always fixes the issue. When USB devices aren’t working, displays connected to the dock (both USB-alt and DisplayLink) do work and the laptop charges.
The dock is 5 months old but this has happened since new. Using all original Plugable power and USB-C cables.
Thank you for contacting Plugable support! Sorry to hear about this issue. I’d be more than happy to assist you.
USB device detection problems like this are a known issue at this time with M1 Macs and the UD-ULTC4K. We have some information and suggestions here: https://kb.plugable.com/question/825145
Unfortunately, as of macOS 11.3.1 we still do not have a known permanent solution. However, we have not retested after the most recent 11.4 macOS release this week to see if the situation has changed.
Please don’t hesitate to let us know of other questions.
Thanks again for contacting Plugable support and best wishes!