Something might or could be really really wrong with corner/aero snap + window resize in Plasma

Example use case: Drag a tiny Firefox window to the top-left corner & make it snap into a remembered bigger size, for example 1/4th of the screen area. After that either click-drag the bottom-right corner or use super+rightclick-drag to resize this Window. Shrinking is really smooth, but enlarging LAGS like crazy. This is a big problem on X with a 1000hz polling rate mouse, a minor inconvenience with a 125hz mouse, but on Wayland the lag is insane.

What’s funny is that if the window is not cornersnapped, but has nearly the same geometry, but 1mm off from the screen edges, then everything is working fine. I talked about Firefox, because as a very heavy app that is a very big offender and all of this is very obvious, but I can get Kitty & Bottles lag this way, well with cornersnapped resizing, or to be more specific enlarging.

I’m using Endeavor OS on my current PC that is using a Haswell igpu, but also tried it on a very fresh Arch install on another Intel PC, where nothing has been set up (stock KDE+ wayland session installed) & the behavior is exactly the same, with a ps/2 mouse to boot. (obviously I’m using up to date plasma5 packages from the Arch repos)

When the lag happens ‘journalctl’ sometimes tells me that I have crazy miliseconds of libinput lag hey slow slow PC, but there is nothing else…

Any ideas what could be done on my side to fix this? Is there an fps limiter setting hidden somewhere perhaps?

(It’s similar in the Plasma 6 alpha as well. Everything’s fine until windowsnap)

I realize this is an older post, however this has been driving me crazy for the last month. Sometimes it takes entire seconds to resize a Firefox window Ive dragged to the edge of the screen. Here are the neofetch pasted for reference.

                     ./o.                  false@false-pc 
                   ./sssso-                -------------- 
                 `:osssssss+-              OS: EndeavourOS Linux x86_64 
               `:+sssssssssso/.            Host: MS-7C37 1.0 
             `-/ossssssssssssso/.          Kernel: 6.6.4-arch1-1 
           `-/+sssssssssssssssso+:`        Uptime: 21 hours, 55 mins 
         `-:/+sssssssssssssssssso+/.       Packages: 1821 (pacman) 
       `.://osssssssssssssssssssso++-      Shell: bash 5.2.21 
      .://+ssssssssssssssssssssssso++:     Resolution: 2560x1440 
    .:///ossssssssssssssssssssssssso++:    DE: Plasma 5.27.10 
  `:////ssssssssssssssssssssssssssso+++.   WM: KWin 
`-////+ssssssssssssssssssssssssssso++++-   Theme: [Plasma], Breeze [GTK3] 
 `..-+oosssssssssssssssssssssssso+++++/`   Icons: [Plasma], breeze [GTK2/3] 
   ./++++++++++++++++++++++++++++++/:.     Terminal: konsole 
  `:::::::::::::::::::::::::------``       CPU: AMD Ryzen 7 5800X (16) @ 3.800GHz 
                                           GPU: NVIDIA GeForce RTX 3090 
                                           Memory: 11264MiB / 32014MiB