I found what the problem was, but I don't know which config was responsible for the old control settings.
Because of the change in control logic, in the last patch, some players had problems with the controls, because the buttons became contradictory and could not be reassigned because of that.
I just completely reinstalled the game and the problem was solved, even though I lost all my customizations. (Don't forget to delete all the configs that you lose from the game. By default: C:\Program Files\Steam\steamapps\common\Deadlock\).
It seems like I could have just deleted the config and run a file integrity check, but I wasn't sure where it was and didn't have the energy to look for it, so I chose to just uninstall everything and reinstall.