Guys.
I need to confirm this before posting issue to bugzilla.

i'm on latest fedora and some recent updates before (month or 2, i didn't catch exact interval ) the issue starts to appear.
While krusader is run it becoming slower and slower and to end of a day about several seconds need to open menu, or just switch to another panel or scroll and so on.

there is no unusual metrics in ps or htop, no unfinished threads (related to krusader pid)

non of other kde software affected

Sounds like some memory loss, I don't use krusader myself, but filing a bug is always a good idea. I doubt this can be solved in the forum.

FWIW: "Latest Fedora" is not really a helpful information, we need the version of krusader and the exact Plasma version, keeping in memory which versions are in which distro release is just too much.

I can confirm this too.
After an hour or so it starts lagging, so I have to restart it, but the same happens all over again.

I'm on Kubuntu 20.
Krusader version 2.7.2 "Peace of Mind"

as above, please file a bug report or subscribe to the existing one and give the link here so those affected can follow it.