/bug is broken for quite a long time, as well as F2. It works (or doesn't work) the same for everyone.

It is likely that Left Shift is set as your "modifier key." Modifier key is used for combinations of key presses with any other key. Defaultly, you dash and shield bash by clicking with one of your mouse buttons while holding down Left Shift (modifier key). If you want to use Left Shift for something else, you will need to replace it with some other key. There is a row called "Modifier" in your controls settings.

I hope I helped you and that my reply was understandable.