Great! The solution was given to me by u/Zamundaaa on Reddit when I made a post on that issue, he pointed me towards this : Environment Variables · Wiki · Plasma / KWin · GitLab
@locklann, can you share that post? I think that discussion might prove insightful for all of us.
Of course, albeit there isn’t much more than what I explained, here you go :
https://www.reddit.com/r/kde/comments/18tqx2k/laggy_display_when_using_egpu_on_fedora_kde_spin/?utm_source=share&utm_medium=web3x&utm_name=web3xcss&utm_term=1&utm_content=share_button
Thank you man, i’m on Debian and this worked, i’ve been digging the internet for 2 half days already !
I’m using Debian with KDE Plasma and running “kwin --replace” just glitched my desktop, a reboot was necessary and after that everything went perfect !
Also, for people willing to try this, don’t simply copy this solution, identify your video card first to replace the appropriate values in the string as explained in the solution.
Thanks again for sharing the solution !