Microsoft has admitted to the presence of a bug in Windows 10 Version 1809 that results in the slow shutdown of devices with USB Type-C connectors. This bug is linked to USB Type-C Connector System Software Interface (UCSI) software implementation in Windows 10.

Microsoft confirmed the presence of this issue on its official USB Blog.

FAQ: Why does my USB Type-C capable system take longer than expected to shutdown?

My system takes a long time to power down if a USB Type-C device, dock, or charger is plugged in or unplugged during the power transition.

A bug in the USB Type-C Connector System Software Interface (UCSI) software implementation in Windows 10, version 1809 can cause a 60 second delay in the system sleep or shutdown process if the power-down happens while the UCSI software is busy handling a new connect or disconnect event on a USB Type-C port. Apart from the extra one minute the sleep or shutdown process takes in this circumstance, this bug does not affect normal functionality of USB Type-C on your machine. The system and the USB Type-C ports should continue to function properly after the next wake or restart of the system.

But Microsoft failed to provide a solution or any planned fix for this issue in the post. Hopefully, a fix is coming soon for this bug.