I have this issue all the time, every invoice, all the time, ALL THE TIME!!!!!.  The print function for the invoice has some algorithm going on that decides the line order and overrides the order I have selected. I choose a nice logical order that takes the client through the invoice 'story' and then AB screws it up.  ALL THE TIME did I mention that.

Never used to happen in desktop and drives me mad.  Yes I've tried the pointless waste of time private window nonsense.