Dark souls 2 sotfs stuck at 720p in gamescope

I’m trying to play dark souls 2 with the graphics overhaul mod in hdr. I’m passing 1440p to gamescope with the -W, -H, -w, -h options and limiting framerate to 60 with -r and -o.

The game just refuses to display at anything other than 720p. I can change the in-game resolution setting to 1440p but the resolution just doesn’t change. I tried setting a lower resolution (480p iirc) as well, but it still looked the same. Also tried enabling fullscreen but that setting doesn’t save nor does it do anything.

I’m inferring that it’s 720p because the in-game cursor moves half the distance of the actual cursor with gamescope set to 1440p, but they’re in sync if I set it to 720p. To the eye it just looks blurry. The mod menu opens at the size it opens without gamescope but is also similarly blurred. Couldn’t interact with it to confirm the resolution due to the aforementioned mouse issue

Outside of gamescope fullscreen works fine and the resolution setting works too iirc (but they reset after reopening the game). Kde plasma. Tried disabling secondary screen, setting scaling to 100 and limiting desktop fps to 60, didn’t help

Could this be some kind of steam deck detection? Any ideas?