Notepad++ all of a sudden very slow with high XOrg CPU usage

I started using Notepad++ years ago, probably when I was still on Ubuntu 14.04. It has been working perfectly until last October when, all of a sudden, the software became as slow as a snail. Opening it takes somewhere between 15 seconds and a minute. How long exactly varies.

Graphical components in the Notepad++ window load slowly, one-by-one. Especially the plugins manager window is very slow to load and there are hardly any plugins activated (only Mime tools, Npp Converter and NppExport).

During start-up the CPU usage of the Xorg process is high, 90-100%. It drops to 0-30% after startup and goes back to 60-90% when scrolling through a small text document.

My question is: how can I troubleshoot this?

Things I tried:

• Scrolled through the /var/log/apt history to see what was updated. There was an update of snap snapd:amd64 (2.56.2+22.04ubuntu1, 2.57.4+22.04), so my guess is that caused the issue.
• Upgraded from Ubuntu 20.04 to 22.04.
• Uninstalled and reinstalled Notepad++ using Ubuntu software center.
• Under Software & Updates → Additional Drivers, I tried to switch to a different NVIDIA driver. This failed with errors.

Eventually I installed Wine and Notepad++ manually and that gave me good performance again:

1. Install wine:

   sudo apt install wine
   

2. Install windbind:

   sudo apt-get install winbind
   

3. In the home folder create the .wine/drive_c/Program Files/notepad++ directory:

   mkdir -p "~/.wine/drive_c/Program Files/notepad++"
   

4. Download the latest Notepad++ zip file from https://notepad-plus-plus.org/downloads/ and unzip it in the folder created in the previous step.

5. Run:

   wine start "C:\\Program Files\notepad++\notepad++.exe
   

During start-up I do see errors such as:

0068:err:winediag:is_broken_driver Broken NVIDIA RandR detected, falling back to RandR 1.0. Please consider using the Nouveau driver instead.

but it works and is again as as fast as it used to be.