cell in base file not showing up correct scale in sheet view

I have a base file that is 30 scale with cells at that scale. The base is referenced into many sheets at 30 scale & all the cells are fine.  I have one sheet that is 50 scale but I cannot get the cells to show up at 50 scale in the sheet view, they are still 30 scale, even though in the default view they are fine (showing up at 50 scale) as soon as I toggle to sheet view they go back to 30 scale.  I can't figure out what setting (s) I need to adjust.  Thanks!