I just replaced my 6 year old MBP with a new 16" MBP which requires the addition of adapters to connect just about anything external. So I got a USB-C hub with HDMI, RJ-45, USB-3.1 and SD card connectors. If it helps, it is from Networx, model no. Y-9115-S. It works, but gets ridiculously hot (40 - 50˚C) with only a USB stick or an ethernet cable plugged in.
No, I am not running ffmpeg on the hub's internal processor.
This happens with the hub on both the left and right side ports. It comes with its own power supply but I don't use it and run the hub unpowered. The hub temperature certainly is a design flaw in a first-generation product, but I wonder if it is normal. Have others experienced the same or is my hub defective?