While looking for similar posts to my problem I found one topic from 2016, when a user complained that while exporting the video his CPU would be 99% used.
The answer was that it is a good thing - and I would find that too.
Currently, when I export a video on my WIndows 11 computer, the CPU only goes up to about 75%, and it will only stay there while Shotcut is actually the active window.
Now that I’m writing this (Firefox is the active window), the CPU usage goes down even though the job is not done yet.
I remember two versions ago or so, the CPU was at 99% while rendering.
I did not change the output settings (libx265, GOP 250, B-Frames 3).
The bad thing is that I really don’t know whether this is something that was changed in Shotcut or if some Windows update hits the brakes here.
It’s not an urgent problem, I can live with it, but I would definitely like to know why Shotcut does not reach its peak anymore, concerning CPU usage.