The HDMI IN to USB-C convertor kit (R9861581) is intended to be used for 2 use case only:
The front USB Type-CTM port used in combination with the HDMI-in to USB-C convertor, can be used as HDMI
input. This port supports the Wired RoomDock functionality where the camera will be displayed on the PC screen
Usage of any other HDMI to USB-C convertor is not supported!

1. HDMI input

To connect HDMI sources to the Base Unit this converter kit must be used. It enables to connect an HDMI source to the Base Unit and a USB Type-CTM port remains available.

To use the converter kit as a HDMI input, you need to enable DisplayPort over USB-C in the Base Unit Configurator (Display & Audio > Inputs). For more info see the Installation manual CX-50 Gen2 Installation manual - Barco

2. Wired RoomDock

With Wired RoomDock, the user can share high resolution and frame rate content and connect to the room audio and video over a wired connection.

To use the converter kit for Wired Room Dock, you need to enable Wired RoomDock in the Base Unit Configurator (Display & Audio > Inputs). For more info see the Installation manual CX-50 Gen2 Installation manual - Barco
See what is wired RoomDock with ClickShare CX-50 Gen2 What is Wired RoomDock with ClickShare CX-50 Gen2? - Barco for more information on how to use the converter kit for Wired RoomDock,

Wired RoomDock using the HDMI IN to USB-C convertor kit (R9861581) is supported from FMW 2.15 onwards.