I’ve had the same issue on Garuda (so probably regular Arch too). Was able to fix it by just going to /dev/input/by-id and setting chmod 000 on usb-Framework_Laptop_16_Keyboard_Module_-_ANSI_FRAKDKEN0100000000-if02-event-joystick and usb-Framework_Laptop_16_Numpad_Module_FRAKDKEN0100000000-if02-event-joystick.
I need to do it every time I reboot, but that’s about it. Meant to put up a PSA here back when I first ran into it (it actually totally breaks input for some games) but totally forgot, so sorry and thanks for reminding me.
Oh, and you may need to restart Steam (and anything else like AntiMicroX or whatever) after doing that for it to forget about them.