I'm interested in this as well, it's something I've noticed on a lot of flights - sitting in the window and looking at the actual wings banking, so definitely not a mistaken seat of the pants feeling.
Often a shortish turn in one direction, before then making a larger turn in the opposite direction. Or vice versa. And on clear days without any visible weather around. I've noticed it more on short haul where I have a window seat more so it's not about entering oceanic airspace. I've always wondered, what else could it be?
I also have noticed the other situation the OP mentions, where the aircraft sits wing low for a loooong time after a turn. I've noticed both these things quite a lot so assume you guys can fill us in, thanks!
