How to cancel key signature before adding new one?

So, in the score I'm making, I change the key signature from an f# minor to an f minor. When I do this, the new key signature has the needed flats, but it doesn't show any naturals to cancel out the sharps. Is there a way to do this? I have a screenshot attached that shows the key signatures are doing currently, and I want the naturals to be before the second key signature. Any help would be greatly appreciated.