Suchiman

Yes at least 5 times. This is not something specific about using the portable version, is it?

This version (contrary to stable) seems to run into issues with gsync, if you have gsync enabled for windowed applications (does not happen if gsync is only enabled for fullscreen apps). When the app gains focus or you move the cursor across it, the refresh rate will drop as low as the monitor goes, causing at least in my case very visible flickering and choppy movements, occasionally but hard to reproduce, it will also lag windows behind if you drag them. If you wait for a few seconds, it stabilizes again and if you actively draw on the canvas, the refresh rate stays high but also not perfectly locked. Here's how that looks, with monitor visualization of refresh rate enabled: https://imgur.com/a/Rzj33c7

I made a screenshot with alt + print of some window, opened paint.net (wasn't open before) and as soon as the window appeared i pressed ctrl + alt + v to paste the screenshot into a new image. Unexpectedly paint.net crashed, but i wasn't able to reproduce it. pdncrash.txt