Frame Selected activates on W instead of F

I've got an issue with my Unity Editor: sometimes the Frame Selected function, normally set to F hotkey stops reacting to in and instead activates on W. Frame Selected from the Edit Menu still lists a proper hotkey, and there's no evident reason why and when it happens. The issue is a pure torture if it happens when I am working with large terrains or something else that requires to move camera around a lot and switch between Move, Rotate and Transform modes for placeable objects. So far, the project I am working on is the only one where I've run into this issue.

How do I prevent it from happening?