Bottom Line: Try toggling these settings on and off if your three and four finger swipe gestures stop working on your MacBook.
On rare occasion, I’ve had my three and four finger swipe gestures stop working on my 2009 MacBook Pro. A restart generally fixes the problem, but the other day I found a solution that worked without as much disruption. If this happens to you, try toggling these two settings.
System Preferences -> Trackpad -> More Gestures -> Swipe between pages, Swipe between full-screen apps
If it doesn’t work at first, try toggling them off, relaunching System Preferences, then toggling them back on.
If you still don’t have any luck, go for the restart. If that doesn’t work, I don’t know what to tell you. Good luck!