scroll in pp-scrollable section using arrow keys of keyboard

First of all thanks for this plugin , it is wonderful . I m trying to use this plugin with four section .

3 sections are of height,width 100% withover flow hidden. and the fourth section has class pp-scrollable which allows me to scroll with more content. (lets say it longSection)

when using arrow keys of the keyboard, I come from 3rd section to longSection it shows me the scrollbar but I am not able to scroll below until or unless I click anywhere on that section. When I click on any part of the longSection it works fine.

I have tried triggering click on that section using jquery. but jquery click event triggered is not an orignal event so it didn't worked for me. also same problem with focus.

hope u can help and fix the issue or if i am wrong then do correct me .