Is this bug reproducible?
Which devices did this bug appear on and is it reproducible on any devices?
A quick summary of the bug:
Navigation completely broken in landscape orientation after extended use of 1PW. Specifically when you select categories the folders list is displayed. If you select folders the last selected category list is displayed. If you switch to portrait orientation then the problem doesn't exist but switching back to landscape and you get it again.
Detailed Step-by-step instruction on how to reproduce it:
I can't find a procedure to reliably recreate the issue but I've experienced it several times today. Quitting the app from the fast switcher seems to rectify the problem.