Firing mod change randomly

Since the new patch, the firing mode changes randomly in the game, making it completely unplayable. I paid 70 euros for this, so it really needs to be fixed as soon as possible. I tried unbinding the firing mode, but it didn’t help — for some reason it still decides to switch modes even though the firing-mode selection is unbound. I also tried resetting the entire configuration, but that didn’t help either.
Please fix this as soon as possible or refund my money!