Hey, I’ve been experiencing the same issue on two computers.
This started happening after upgrading plasma-workspace (and dependencies) from 6.4.5-4.fc43 to 6.5.5-1.fc43.
I’ve tracked it down to the upgrade of kdeconnectd from 25.08.2-1.fc43 to 25.12.1-1.fc43.
Temporary solution that seems to work is to remove KDE Connect:
# dnf remove kde-connect
Package Arch Version Repository Size
Removing:
kde-connect x86_64 25.12.1-1.fc43 <unknown> 4.2 MiB
Removing unused dependencies:
fuse-sshfs x86_64 3.7.5-1.fc43 <unknown> 125.4 KiB
kde-connect-libs x86_64 25.12.1-1.fc43 <unknown> 2.4 MiB
kdeconnectd x86_64 25.12.1-1.fc43 <unknown> 67.5 KiB
kf6-kpeople x86_64 6.22.0-1.fc43 <unknown> 671.2 KiB
libfakekey x86_64 0.3-25.fc43 d15e557246b143e68b4d7cf7c8078e9c 45.5 KiB
openssh-askpass x86_64 10.0p1-6.fc43 <unknown> 19.7 KiB
qt6-qtconnectivity x86_64 6.10.1-1.fc43 <unknown> 1.5 MiB
Transaction Summary:
Removing: 8 packages
After this operation, 9 MiB will be freed (install 0 B, remove 9 MiB).
Is this ok [y/N]:
After logging out and logging back in, stutters were gone.