Maxing out Xorg CPU after Kubuntu 24.04 upgrade

[dmccurley]

I upgraded my new computer to Kubuntu 24.04 installed Winbox. Winbox takes minutes to start and then is unusably slow. It takes forever to draw screen elements and respond to any mouse clicks. htop reports that Xorg is maxing its cpu, while the other cores are almost unused. My old computer running Kubuntu 22.04 with an older nvidia card had no issues running winbox. Killing winbox results in xorg cpu usage dropping down to normal.

To Reproduce
Steps to reproduce the behavior:
Upgrade to Kubuntu 24.04 on a machine with an nvidia card. nvidia drvers are:

nvidia-firmware-535-535.171.04
xserver-xorg-video-nvidia-535

Expected behavior
Functional and responsive winbox.

Distribution (please complete the following information):

• Name: kubuntu
• Version: 24.04
• Architecture: amd64

** snap version **

snap    2.63
snapd   2.63
series  16
ubuntu  24.04
kernel  6.8.0-31-generic

** snap info winbox **

name:      winbox
summary:   small utility that allows administration of MikroTik RouterOS
publisher: ThePanaceya
store-url: https://snapcraft.io/winbox
license:   unset
description: |
  Winbox is a small utility that allows administration of MikroTik RouterOS using a fast and simple
  GUI.
  
  Snap conatins Wine runtime and winbox client.
  
  Readme: https://github.com/panaceya/winbox/blob/main/README.md
commands:
  - winbox
snap-id:      UdK6K4ZjRfjL0wRFh0tWGO7vPhA4Qge4
tracking:     latest/stable
refresh-date: today at 21:47 EDT
channels:
  latest/stable:    3.40 2024-05-18 (170) 47MB -
  latest/candidate: ↑                          
  latest/beta:      ↑                          
  latest/edge:      ↑                          
installed:          3.40            (170) 47MB -

** snap list winbox **

Name    Version  Rev  Tracking       Publisher    Notes
winbox  3.40     170  latest/stable  thepanaceya  -

Additional context
I searched for a couple of hours and found some reference (lost it now :( ) to a problem with xrandr extension for nvidia but I didn't have this issue on older nvidia and I don't have an /etc/X11/xorg.conf to try locking the screen resolution like they mentioned.