i had the same problem with my Avant.
Some kind fellow enthusiast posted the following and it sorted it out..............................
Hi under format 1 there are 3 "sub formats" 4/3 - 14/9 and 15/9 or 16/9 depending on model.
the thing is: you last used "sub format" is the one it will use as default when in format 1. you change the sub format by << - >> or up and down (depending on model) when it's in format 1.