I have an HP ProDesk 400 G5 micro tower model that has 2 built-in USB 3.1 ports. Kubuntu 25.04 is installed. I have purchased 2 USB to USB-C adapters, and I want to use one of the ports for a 2.5 Gbps USB-C network adapter, as I have a speed of 2 Gbps when connected via cable to the router. However, I cannot achieve a higher speed than 120 Mbit download and 300 Mbit upload. On my laptop, I can easily achieve a speed of just over 2 Gbps via the USB-C port with the same network adapter. I hope someone has a solution to the problem. Of course, I can just use the RJ45 port, which supports 1 Gbps, which is a good speed. But I would like to take advantage of my 2 Gbps connection on the desktop computer 
It is highly unlikely this is related to KDE at all. Network speeds are determined lower in the software stack.
1 Like
I forgot to mention that my laptop also runs Kubuntu 25.04. So KDE is not the problem.