Ok, I think I see something now...
if I change the mash temperature in the temp box of the mash guideline section, even if I hit "save" at the top of the page, it wont do anything to abv or fg. the new temperature will be saved in that box though.
IF I put a new temperature in the mash guideline box and hit ENTER, then it is changing those abv and fg figures even without "saving" . that is weird since any other entry box in brewers friend just requires you to type a number and done, it automatically updates the recipe.