Hi Mary, sorry for the delay, but just enabling Personalized Navigation shouldn't have even been able to change your Kanban board settings.
Just taking a guess that perhaps you were viewing a different Kanban board or you had one on a certain custom page in the old nav?
I recommend ensuring that you are viewing the same page with the same project scoping in Personalized Navigation as you were viewing on old navigation - please let us know if it's still different and we'll be happy to investigate further!