SaT grabs the blind size from the titlebar of the table. It currently does not detect if you are displaying stacks in BBs. The same problem exists on Stars, Party, Winamax as far as I know. You'll need to keep stack sizes displayed in real values.
Alternatively you can try using other hotkeys like BetSizeX or BetPot%
Alternatively you can try using other hotkeys like BetSizeX or BetPot%