When running a slightly complex example app like the "Coffee Machine" example, the qmlscene puts one CPU core under load, even if the application is not visually animating anything.
I noticed that because the cooling becomes louder.
This does not happen with applications straight from the wizard. So, some specific Quick item might be causing that (reminds me of
Edit: This happens for me with the Qt5-based and Qt6-based kits in QDS.
My Graphics drivers:
Dynamic GL LibGL Vendor: Intel
Renderer: Intel(R) UHD Graphics 630
Version: 4.6.0 - Build 126.96.36.19964
Edit 2: The cause seems to be the Multilanguage Database feature.