[2.1.9] Linux: Assigning controls always results in KEY_0

[Ferlonas]

I'm currently in the process of switching away from Windows to Linux, specifically CachyOS (Arch Linux). I'm running Steam as Flatpak package, and from that, Factorio. It runs perfectly fine. There's just one problem:
Assigned keybinds (single key and combinations) can be used, but if I try to assign new ones, it always, no matter what key I press, results in "KEY_0" being assigned to that action. Pressing "8" -> KEY_0. Holding Control to press 8 -> KEY_0 as soon as I press down Control.

This is only happening in Factorio, not in any other games launched in the same way. It doesn't seem to be a matter of input recognition, as keybinds work fine in-game if they are already assigned.
Just tested: This also happens in the native client when launched without steam.

I've attached two logs, one with mods and one without (the modded one contains three extra errors related to keys - perhaps they can serve as breadcrumbs).

Factorio version: 2.1.9 experimental
OS: CachyOS Linux
Desktop environment: KDE Plasma 6.7.2 (Qt 6.11.1)
Kernel version: 7.1.3-2-cachyos (64-bit)
Graphics Platform: Wayland
Keyboard: Cherry G80-3000N RGB