Game crashes ~90 % of the time when rebinding character-specific alt-fire to a key on the keyboard

[Oakum]

It sometimes also crashes when clearing the same keybind. Does not happen when changing the general keybind, only character-specific. Does not happen when binding to a mouse button. Seemingly only happens with alt-fire, not with regular shooting or abilities. I have verified game file integrity and restarted the computer, and the behaviour persists.