Photo Albums out-of-order
I do not use Photos or iPhoto to sort / store my pictures on my Mac. Instead, I maintain a separate folder with subfolders based on either date or event / project. This is a bit of throwback to my pre-Mac days and also a bit of belt and suspenders against proprietary software and to be able to access them on a variety of devices. Anyway, I've directed iTunes to that main folder and chosen subfolders to sync to my iPhone (6) and it includes this is in it's sync - which then show up in my iPhone, with these folders in place. This process has always been the one I have used with no issue.
However I have found that over several syncs (mostly wireless), the order of these folders goes completely wonky - or sometimes double - in random order. The only way I can fix this seems to be to (via hardwire) delete the photos from the iPhone and then re-add them (Sync Photos) - everything seems fine and then it starts again over time