Serial includes built-in support for the FT232R, FT232B, FT232H, FT2232H, FT4232H, FT230X, FT231X, and FT234X bridge chips along with the FT260 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 Therefore, a problematic or outdated kernel driver can affect your experience using Serial.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 FTDI 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 AppleUSBFTDI driver for some FTDI devices with macOS 10.9 (Mavericks). While this driver has improved over time, it still lacks complete support for some FTDI devices and features.
To resolve the issue you have two options:
Disable the Apple driver - see How to Disable a Kernel Driver .
Install the official driver. This driver is well written and will take precedence over Apple's driver and correct the situation.