Serial includes built-in support for the CP2101, CP2102, CP2102N, CP2103, CP2104, CP2105, CP2108, CP2109 bridge chips along with the CP2110 HID bridge chip.
Due to the architecture of macOS, when a kernel driver binds to a device it blocks Serial's built-in support for that device, forcing Serial to use the kernel driver. Therefore, a problematic or outdated kernel driver can affect your experience using Serial. To determine which driver is being used to access your device, see How can I tell which driver is being used to access a device? .
The official driver provided by Silicon Labs is well written and is recommended if you need to install it so other programs can access serial ports on your computer. Please make sure your driver is up to date to avoid potential problems.
Apple began shipping their own driver, "AppleUSBSLCOM", for some Silicon Labs devices with macOS 10.15 (Catalina)1. If you're running 10.15 or later, you may have noticed this new driver binds to all devices in the CP21xx family of devices even though it only supports the CP2102.
To resolve the issue you have two options:
Disable the Apple driver - see How to Disable a Kernel Driver .
Install the official Silicon Labs driver. This driver is well written and will take precedence over Apple's driver and correct the situation.
Apple appears to have removed the problematic driver as of macOS 10.15.3. ↩