SUMMARY
I'm using Fedora 40 with the 6.10.11 Kernel. As soon as the graphical interface starts (e.g. graphical login) the whole system grinds to a near hold. The mouse reacts only once or twice a second. Keyboard inputs are delay by about a second and sometimes registered multiple times, which makes it near impossible to use the system.
In htop i see that /usb/bin/kwin_wayland is using all 16 threads at 100% and it is not going down over time (at least not in the first 30 minutes).
I tried changing to i3 which works fine, so i assume that this is an issue with KDE?
The kernel-logs look good to me and the journalctl mostly shows warning like "error creating screencast Could not find window id {..."

STEPS TO REPRODUCE
1. Booting the System
2. Problem begins as soon as the login screen is rendered

OBSERVED RESULT
100% CPU Load and delayed mouse and keyboard input.

EXPECTED RESULT
Low CPU usage at idle and fluent mouse and keyboard input.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Fedora 40 6.10.11
KDE Plasma Version: 6.1.5
KDE Frameworks Version: can't check since the settings app won't open
Qt Version: can't check since the settings app won't open

ADDITIONAL INFORMATION
CPU: Ryzen 3700x
GPU: MSI NVidia 3080
Mainboard: Aorus x570 Elite

Any help is appreciated.
Thank you in advance.