Need help with PDF view settings in Preview.

Hi folks,

I'm going out of my mind here and need some help.

I just updated the OS on my iMac and I've noticed one frustrating change. Before the update, whenever I opened a PDF document in fullscreen on preview - I could use the magic mouse and swipe my finger from left to right to flip between the pages.

I can't seem to be able to do that anymore. Now the only movement preview accepts is an up/down motion on the mouse and the pages change automatically. There isn't a smooth 'transition' as there was before.

Does anyone have any idea what's going on or how to revert it back? I've tried looking through the settings/preferences SO many times and I can't seem to see any clear solution.

Thanks.

 

Anyone have any ideas how to fix this? Going out of my mind here!