Previous button taking me to last visited page

Hi, I have a lot of long courses at the end of which there is a Review option. Each slide has a previous button that takes the user back to the previous slide. However, on the last page, if the user has used the review button, they are taken back to the review option rather than the previous slide. To fix it, I assigned the particular slide number for the previous button on the last page. However, now this gives me another issue as the penultimate page's previous button now takes me back to the last page instead of the previous page. It seems like the previous button is set to show the last visited page. The workaround is to change trigger on each previous button and specify which page it will go to. But this is inefficient, makes the work difficult and increases chances of error (what if I insert a new slide? I will have to tweak the triggers again). And changing all the previous buttons on almost 100+ courses is not feasible at the moment. 
Any suggestion? Workarounds? Fixes?